I always agonize over breaking set bonuses. You can sim it out all you like, you can run dummy tests, you can hit up LFR to test it out, but at the end there's always that brief period of self doubt over abandoning a set bonus for overall higher stats. My current raid had something like four warriors, four hunters, and a fair amount of shamans and monks so I'm not even trying for tier right now, instead focusing on overall upgrades. So last night, after getting a nice DPS ring and breastplate, I decided to break my Tier 14 4 piece set bonus.
To be honest, my performance seems to have improved, and I find myself wondering if it's because I raid as arms, since we don't get the double-crit on Mortal Strike that fury gets on Bloodthirst. I did do some LFR after the raid as fury, but my weapons are significantly below my arms weapon (since I can't use a polearm with Titan's Grip and I haven't gotten squat for SMF in two tiers of raiding) so in the end it felt like a wash. Heck, in order to even test TG I had to do an item restore on my upgraded Starshatter.
One of the issues facing us as DPS warriors is the idea of maximum DPS by spec. A lot of people will use sites like Noxxic, look up what the maximum DPS is for their class by spec, and just spec that. It doesn't work, and they get frustrated. Based on a conversation I had in LFR last night, I'm doing everything imaginable wrong by speccing arms as a DPS warrior, and I found myself forced to defend my spec choice even while outperforming everyone else. In fact, it seemed to irritate said person that I was doing what he said couldn't be done. Now, let me be clear that this isn't Noxxic's fault - it's a poor craftsman who blames his tools, and it's a worse craftsman who tries to use a power drill as a belt sander. But let's talk a bit about the difference between your DPS in a perfect vacuum vs. your DPS in an actual raid situation.
Each actual raid encounter, be it a big trash clear, a boss right with lots of adds like Horridon, or a fight with unusual mechanics like Durumu demands something different from you as a DPS. It may be that you're simply better at one spec's playstyle than another. As a result, you may find yourself performing more reliably as TG fury than SMF fury, even though SMF is ranked higher or sims better for you. A sim is useful for telling you what you could theoretically achieve and is often very useful for informing you when you're doing something wrong - it provides you with a baseline to compare yourself to, but it isn't the whole picture. You need to look at your gear, your spec and glyphs, and your strengths as a player as well as fight conditions. For a long time in Tier 14 I was significantly undergeared and was running Titan's Grip against two SMF warriors, and although I kept hanging in the pack I wasn't breaking any records. I simply couldn't compete because, all things being equal, I had gear and spec issues I needed to address. Interestingly, switching to arms helped my DPS because it outperforms TG at the level of gear I was at. Furthermore, once 5.2 rolled around, the changes to Taste for Blood went together well with my playstyle and I found myself able to hang with other warriors using SMF because I know how to execute an arms rotation well.
It's true that as gear improves, I'll need to consider going TG or SMF. Sims are pretty unambiguous about how their DPS improves as gear improves in a much higher curve than arms. The point, however, is that I have to make that choice based on what I can actually do, not what SimulationCraft says is possible. Again, this isn't any flaw with the simulation tools, and it isn't even a flaw in my ability, or yours. SimCraft is a tool. It's a good tool. (Seriously, you can do a lot with SimCraft, and I'll probably do an entire post detailing it in the future.) But it's only a tool, just as DPS meters and logs are tools. Their purpose is to help you make the best decision possible about what you can achieve. If you're a skilled TG player in 480 gear, switching to arms might hurt your DPS, at least in the short term, if you're not comfortable with the rotation and putting theory into practice. Something as simple as choosing Warbringer over Double Time might help or hurt your DPS depending on how it interacts with how you play.
Are you missing a lot of Raging Blows because you're not noticing you're entering an enrage? Addons like WeakAuras and SlamAndAwe can help you, as well as paying attention to the default UI's warning graphics. Sometimes it's better to save your cooldowns for just before or after a Colossus Smash, or to line up with another raid cooldown like Bloodlust/Heroism/Time Warp. Are you forgetting to drop Skull Banner, or dropping it at the same time as another warrior in the raid? You can work on all of these issues. One of the best ways to find your issues is to get a decent damage meter that tracks your abilities, Debuff uptimes, and so on. Both Skada and Recount should have this functionality. The point here isn't to win an imaginary numbers contest, it's to examine how you did the damage you did and to compare it to what your theoretical perfect rotation would be, and see if you can identity errors you're making. Are you hammering Heroic Strike as soon as you get enough rage and ignoring Raging Blow? Do you forget to use Sweeping Strikes on trash packs? Do you rarely use your cooldowns? (Frankly, I prefer World of Logs to any addon for this purpose, but if you're running LFR or dungeons, you may have to settle for the addons.)
In the end, all of these tools exist to serve you. Don't make your character choices based on blindly obeying what you think they're telling you, use them to inform your choices and base them on what you can do to best put them into practice. That being said, don't be afraid to make changes purely based on comfort. No DPS warrior spec is particularly hard to play, and while there's a difference between proficiency and mastery (and I wouldn't claim to have achieved mastery, personally) you can become proficient fairly quickly. There's a lot of elements to consider in choosing your spec - theortical limits, the gear currently available to you, your familiarity with the spec, the time and resurces available should you choose to change, and even talent choices and how they interact with said spec. Make the best decision for yourself, not for the theoretically perfect warrior out there. And sincerely, download SimCraft and play around with it if you haven't already.
At the center of the fury of battle stand the warriors: protection, arms and fury. Check out more strategies and tips especially for warriors, from hot issues for today's warriors to Cataclysm 101 for DPS warriors and our guide to reputation gear for warriors.