An interesting thing to note about the way the armor penetration system is now structured is that one's benefit from Sunder/Expose is independent of how much armor penetration you actually have. That is: against a typical raid boss, Sunder will cause all your physical attacks to do ~8.7% more damage regardless of how much ArPen you have. And, to be perfectly technical, as you gain more ArPen (relative to other stats), the portion of your damage that you gain from physical attacks tends to increase; hence, the size of the damage boost you get from Sunders (in absolute terms) *increases* as your ArPen does. Hence, in any reasonable level 80 raiding situation, you will never find yourself in a situation where you don't need to worry about Sunder/Expose; even 100% ArPen does nothing to reduce your need.

If the spreadsheet says it's better, it's better. Now, that doesn't mean it's a good trinket for a mut rogue: you just happen to have a rather weak trinket (unless you're hit-starvec of course); DWB thus appears as an upgrade. Unless for some reason no warrior/hunter/Combat Rogue/etc. needs it however, I wouldn't roll on it, as it's an excellent trinket for them. If you're in a position to get a DBW, you're also likely in a position to get a WFS or a TAiaJ, both of which are much, much stronger options for a mut rogue.

Oh I agree. I was quite literally one of the last people to get it (I picked it up in the event I swap to combat). My guild has had the absolute worst luck for the other trinkets (1 normal and 1 heroic drop of WFS in the weeks of clearing. TAiaJ is almost out of the question since we don't consistently kill him.). It seemed like a decent trinket, but the passive ArP really put me off and the idea of regemming for hit. I was just looking for any personal experience in regards to the trinket. Thanks for your speedy reply !

Okay so I've been rolling along as a combat rogue doing great dps generally hitting in the top 3 of 25 man raids for a long time. Had my hit cap and everything all kosher but now i've gotten gear where it brings my hit down below 8%.

I started to gem for hit (really don't want to...Armory hasn't updated but with gemming got it to 7.58) but decided to run the spreadsheet and it is indicating mainly arp gems and 10 agi/10 hit gems. I had been running mainly AP and ap/crit.

Would anyone mind looking at my wow armory and offering suggestions? My gems are a bit of a mess now. Seems with 3/5 Shadowblade gear and Deathbringer's Will, i'm seriously lacking in gear with hit.

Don't mind regemming per the spreadsheet but would like some reassurance.

Could use some help...Thanks all.

You def need to change some gear around. Like picking up bladeborn leggings, which are craft able so easy to obtain. Also you should be gemming Arp, not Ap. I would also try getting Heroic Ikarus for chest, and picking up T10 helm and shoulders. T10 chest is ok though but Ikarus gives you alot of Hit and Exp you are missing. Regular Ikarus is Boe and heroic isnt much harder to obtain.

Ickfirus and bladeborn or tier shoulders and tier legs, you'll have to have one combo or the other essentially. Once you're in full ICC gear anyways.

You are above even the poison hit cap, though, much less the special cap. The spreadsheet is suggesting agi/hit because it's the best yellow gem for your gear and the socket bonuses are worth it, not because you need hit (it's because of your herkuml mostly).

Other than being a miner your gear looks fine.

So I recently read through some of the latest post on the In depth Mutilate cycle thread. Towards the end it was mentioned it might be better for assassination spec rogues to use 2/5 heroic T10 + 3 277 off pieces(Geistlord's punishment sack, Cultists Bloodsoaked spaulders, and Ickfirus) than to simply aim for 4 pieces of heroic T10 and 1 off set 277 piece (Ickfirus). I was wondering what others had to think about the merits to this gearing. It seems like this set up would indeed be better for target swap fights, and also it would cut down on human error and bad RNG. Personally, I have many times seen my 4 set bonus and ruthlessness proc what seemed like 1.5 seconds after I used a finisher, and while this may be due to my mediocre latency or poor reaction time(i hope not the latter) I end up hitting mutilate when I should pool energy. Furthermore, even when I do properly execute my rotation, the 4piece bonus sometimes procs at rather inconvenient times (such as when im sitting on 85 energy, a 4 combo points, and 5 seconds left on my envenom buff), which leads me to believe that in these instances its total DPS benefit is partially wasted. Also, the dps difference between these two gear setups is minor, about 10-15 DPS depending on what you consider plausible BiS gearing.

Any thoughts and advice would be greatly appreciated.
Thanks!

To be clear: to some extent the notion of wasted envenom uptime due to T10 procs (and some similar issues) are modeled; that's part of the reason why the set bonus is worth so little. I can't exactly speak for all the authors of modeling programs, but speaking for myself, I feel like I've done a fairly good job of modeling all effects in play for a single target tank and spank scenario. Hence, when considering the tradeoffs of T10 4/5, I'd focus on those that are based on the differences between a real fight and the idealized Patchwerk scenario.

Which, of course, are fairly significant in their own right - target swapping, AoEing, etc. are all situations where the set bonus does nothing for you. And given that those situations do come up on some highly relevant progression fights - like, oh, say, Lich King - I think it's fair to say that as an average across all fights, the 4/5 set bonus is probably not quite as good as a spreadsheet model might make it appear, even if it's correctly modeled for tank and spanks. Add to this the fact that if my guild in any indication, getting 2/5 + 3offset is a heck of a lot easier than getting 4/5 +1 offset (amongst ilvl 277 pieces, anyway). Hence, I think it's fair to say that there's a reasonable case to be made that 4/5 isn't worth the trouble. There are probably some people who will conclude otherwise, and that's fine; but the decision to go for 2/5 instead of 4/5 is totally reasonable, even if the spreadsheet shows it slightly behind.

Just a simple/quick question that might sound stupid to some people, but does ArPen affect FoK damage at all? I'm guessing not, since the tooltip shows it as a fixed % of weapon damage, but I'm curious and wasn't able to test this myself accurately enough.

ArPen affects all physical damage you do, including FoK.

EP= Equivalence Points
AEP= Agility Equivalence Points
AE= Agility Equivalence

The modeled you refer to I assume means the data reflected in one of the numerous spreadsheets located in this forum.

Have a quick read through this thread it may answer other questions you might have.
Pocket Guide to WOTLK (Updated for 3.3)