It's quite difficult indentifying something as an upgrade now... you need to be a freakin' numbercruncher to or a spreadsheet wizard to figure that out nowadays with all those different stats, sockets and gems. Most of the time it would pretty nice if you could spot an upgrade before you spend 4 weeks of dkp on it before you notice it's just a 0,00001 dps upgrade... or worse; a downgrade.
I'd used to try to figure this all out in advance, checking out all gear in advance... way before we ever got to the boss that could possibly drop it, but it is alot harder now and many other factors to take in account aswell.
Last week i was on a roll and the gods of loot decided to finally toss some stuff my way: Mantle of the Timeless Tracker and Rift Stalker Leggings from SSC to be more precise.
As my hitrating was pretty high now i finally was tempted to replace my "old" Karazhan belt with the crafted Belt of the Black Eagle (not bad for 3 hours farming mats ey?)... but would it really boost my dps?
I decided to finally get an addon a guildmember advised me a while back: WowEquip 0.8
When i started it i was kind of bafled with the ammount of information but it was actually quite understandable when staring at it for a bit longer.
What it does is load all your equipment and generate stats, including enchants and gems of which you can make a profile. The beauty is you can replace any item (just a simple lookup if you know the name), add enchants and gems of your choice and it will compare it to your earlier made profile.
This makes it very easy to compare items with sockets and even various socket options.
But the possibilities are much bigger then that, you can inspect a random person and get all the information of that person using wowequip and compare his/hers stats to yours... or compare to other people to each other. It got enough options for hours of theorycrafting if wanted, or just exist as a relative easy tool to compare possible new gear to your current.
I found out within minutes the pants i replaced are actually slightly worse but the 2-set bonus makes up for that imo.
Also helpfull is that you can see ahead how much hitrating (or any other stat using ratings) you get without needing to convert ratings first.
There is some more info on the Elitist jerks forum if you want to dig a bit deeper into the addon. (here) By the way make sure you download Wowequip 0.8 as there is an external program called Wowequip aswell (executable installer), if you use the link above you get the right one anyway.
The one thing it doesn't do is what i still use a 9 month old addon for: Theorycraft 2.
This one shows on my buttons how much damage a skill does, taking an average of crits in it (if set up that way). A loss in attackpower and a gain of crit could either buff or gymp my dps... that normally requires calculating which this addon does for you.
Until recently DrDamage did the same but just for casters, when trying to get a link for you guys i suddenly notice *Supports all classes* so i intend to give this a try as DrDamage is being kept up to date and Theorycraft2 is not.
Will get back to you on that...