Over a year ago I wrote about the addons any good raiding dps DK needs. Wow, can't believe it was so long ago!
I've actually turned over more than half of my addons, so I thought I'd write a little about them now, realizing that at least some of these are likely to change as their authors may or may not update them for Cataclysm and we're likely to see some new shiny addons come out at that time as well.
I'll copy my format from that previous post and comment on any changes/updates here.
1. Raid Warnings/Events: Still absolutely essential for raiding, despite what some misguided snottydins might tell you. DBM (Deadly Boss Mods) is still the industry standard, but I've converted to BigWigs, as it is less memory-intensive. Both work very well for helping identify important events during a boss fight, and allow some customization of how you want to be alerted (BIG letters on screen? A sound? Both? you got it).
2. Proc Alerts: Blizzard's version is a very nice start, and quite a few bloggers have commented on how visually pleasing their HUD notifications are. As unholy so far, the Dark Transformation and Sudden Doom procs are very easy to identify by their visual alerts. So far, I'm not aware of the in-game system having a Runic Empowerment alert, which would be nice to know so that I could hold off on Death Coils for three seconds (unless runic power is capped and no runes are available). I haven't used Mik's Scrolling Battle Text for a long time: I used Power Auras for a while, but haven't loaded any proc alerts for 4.0 yet. If you prefer auditory alerts, one of these addons still might be best for you. I haven't tested Frost to see if their in-game proc alerts work as well - but I've seen screenies of Rime procs etc that look pretty good, so you might be able to rely on the default system for now, although a Runic Empowerment alert is even more important for Frost than Unholy.
3. Rune/Disease Watch: I'm still a 'thowback,' although I'm not using Rune Hero any more. It remains as important as ever for you to know which runes are ready to be used, which ones are almost off cooldown, and how much runic power you have. Even more importantly, you need to know how much time is left on diseases so you can ensure they don't fall off. The default Blizzard interface fails hugely here and it's very difficult to use their rune display effectively.
I like DKI Runes, and even though my health bar (when I'm being targetted) superimposes on it, it doesn't cause problems with the rune display and I prefer to have it front and center as you can see from the big screenie below.
You have many options - try a few out and see what you like best. DDR is the very popular choice on Elitist Jerks right now (Docs Debug Runes) but I'm not fond of it at all. DKI Runes has (as you can see) a sword-looking addon that is more compact and well-designed than my old fave Rune Hero, and has a nice disease watcher as well. I was a BIG fan of Acherus Runes, but it hasn't been updated and doesn't work for 4.0. One advantage of DDR over DKI is it has a nice obvious display of Shadow Infusion stacks (it may be possible to do for DKI as well, I just haven't discovered it yet).
4. Communication: Ventrilo is still the gold standard. It's the one 'addon' not available at Curse.com. (But download is free at several sites). The in-game voice comm is horrible and I don't know of any raiding guilds that use it.
5. Threat Meter: Threat meters are again relevant for 4.0 and I've noticed it's easier to pull a mob/boss than it was before. We don't have any passive threat reduction, and misdirect abilities have been nerfed. Good tanks still hold threat, but as a raider, you're responsible to watch your threat. Omen is by far the most popular threat meter, and the one I still use.
6. Damage Meter: I realize quite a few players/bloggers out there like to demonize meter-watchers, and rightly so in some cases. If you attempt to simply max dps without paying attention to fight mechanics or what your role might be, you're a bad player. But, when your primary role is to dps, why wouldn't you want feedback on how you're doing? As I've mentioned before, the meter gives you instant feedback that you're doing something right - or wrong. I can't tell you how many times I've noted a drop in my dps - and thanks to the meter - realize that after that last wipe I forgot to summon my ghoul, or after changing specs to pick a presence, and so on. Damage meters for bad players? NO. Bad players are bad players. Good players use damage meters. By the way, I've dropped the resource hog Recount and now use Skada. I still prefer the useability of Recount and may go back to it, but for now Skada is what I use.
7. Attack Power gauge: I was VERY pleased with Bleeding Hearts and had a separate post on it previously, but it seems to cause huge lag problems and sometimes seems the culprit in disconnects. It hasn't been updated in a long time and sadly I've had to delete it. Tiny Melee Stats still works but it's not my favorite. I'm still looking for a good option here. In any case, it's very helpful to see how much attack power you have to help with determining when to summon pets. Now that they also get our haste, it would be nice to have a haste indicator as well. I'd love to see a thermometer type gauge like Bleeding Hearts for both stats somewhere on my screen.
8. Others: For the most part, any other addons are for personal preference and won't contribute to your performance as a dps DK.
-MetaHud, one of my long-time favorites, is currently not working in 4.0. *sadface* The HUD you see in my screenie is IceHud, which is fairly similar and not too bad.
-Grid. You don't need this as a dps DK, but I do like to see who's alive during a fight, or be able to quickly find someone to target their target etc. It's essential for healers/raid leaders, not so much for dps DKs.
-OneBag. This addon broke for me, although I think it works for others. I'm now using Bagnon, which also has a feature that lets you see your bank and/or alt's bags/banks.
-Postal. Makes mailing and opening batches of mail much easier, as well as keeping lists of who you've mailed.
-Carbonite. Somewhat dated these days, so I'm not using it any more. Questhelper addons can still be useful, but the in-game map and tracker work quite well for me now.
-Gearscore. I actually used GS lite for a while, now I don't have either turned on.
-SpartanUI. As I posted more recently, the UI mod I use. It also requires Bartender but the download comes preset for SpartanUI. nUI is also very popular and even has a DK skin, but I've tried it and didn't like it. It's not bad - and is very similar in many ways, it's more a matter of preference. These addons preferably clean up space on your UI and are visually pleasing as well. You can make a case for these helping your raid performance by allowing you to be more aware of your surroundings and being able to find your target easier. I used the default UI for many years and it works just fine if that's your preference.
-Bloodhound. A very lightweight addon for helping gathering (which a dps DK IS NOT, but at the moment I'm mining until 85). There's better ones out there, I just don't need them.
-AutoProfitX. There's a dozen small addons that will dump grey items either automatically or put a button in the vendor tab. Nice to not have to click each one to sell individually.
-AuctionLite. I'm not enough of an Auction House mini-game player to get into Auctioneer. AL does what I need. I dont load it for my DK though - just my bank alts.
-Parsing sites: over the past year I've made multiple mentions and uses of these sites. Back on my original post, I was using WMO Online, which is still in operation, although I prefer World of Logs these days.
-Achievement Screenshotter: I had forgotten to add this one back in and was bummed when I looked for screenies from a couple of achievements my guild got over the past few days. It's back now, and screens from all sorts of random achievements will be dumped in my folders over the next few months.
And there you go - an update on addons that are useful for raiding dps DKs in late Lich King 4.0! (and a few that don't matter, but make life in Wow easier/better). Enjoy!