Sorry for posting if this thread is already dead
I had the same issue a year or so ago when I used crossfire, by the time the diver update was out to fix the negative scaling from xfire, all my mates had already beat the game. I think when skyrim came out it was a good 3 months before the negative scaling was fixed. on such a huge release I was so eager to witness the power of twin gpus ... I agree also on the games that it did work, I probably spent more time tweaking the radeonPRO settings to get it working then I did playing on 90% of titles. Then the tech guy at my local PC store suggested I just get a single nvidia card (I was a complete radeon fanboy at the time because I had been gaming since playing helicops and mechwarrior on my first pc *pentium2 233mhz*, back when I changed from a voodoo card to a radeon and never looked back) The performance gain after installing the new card astounded me. Not even in games just ... using the desktop ... or anything ... it was all just better. Now my cousin just got a second GTX660ti for SLI and I spent an afternoon/evening at his place, ready to laugh and scoff when all his games started providing worse fps, or wouldn't even load. Oh how I was wrong. EVERYTHING he loaded was massively improved. (Not double of course but probably about 50% better on average) Everything from World of Warcraft to Crysis to Alan Wake to Civilization5 to Metro 2033 to The Witcher 2 to to Black Ops 2 and even older things where the performance gain is irrelevant like half life 2. CS source and garys mod, and COD 4, everything just worked, and worked better. No third party programs, no hours of loading the game, testing a scene, exiting, changing a setting, loading the game, testing same scene ... you get the point. Now he has set up his 3D surround vision and while I haven't personally seen it yet, he says it works amazing. Why everyone who uses Radeons aren't up in arms and boycotting their terrible terrible products is beyond me.
Don't know what to tell you, I am in the same boat, I work hard to pay my bills and save for high end PC gaming hardware as a hobby. I would (and was) greatly dissapointed with spending my hard earned cash on (in my opinion) a complete lemon. Maybe AMD execs are sitting in their penthouses laughing their asses off at all the idiots giving money to them for their bad products. Theres only so much having a good name like RADEON can save you. Honestly I hope AMD start improving their products and restoring their name, because right now Intel and nvidia have no real comptetition (for gamers), and competition keeps the market alive, keeps the developers developing, keeps the industry rolling.
My second ASUS OC DIRECT CU II GTX 670 should arrive sometime this week.
Wish you all the best and happy gaming!