From a raiding standpoint, by the most competitive guilds, Naxxramas/Malygos/Sartharion were way too easy. The achievements gave them a bit of a challenge (see Immortal) but most had still won the game by January.
For the rest of us raiders, like myself, achievements stretched out the raiding experience right up to Patch 3.1 released today. Like many scrambling to get done, I got one of the elusive drakes just this week, but the other will forever be out of my reach.
Achievements gave me a new reason to keep raiding, but it wasn't necessarily a good thing. Just like fake goals I've set up in the past. For instance accumulating offspec gear, piling up badges or deciding to reach max exalted with the instance's reputation. I found myself raiding but not for the raid experience. I personally raided a month or so longer than I should have. But achievements prodded me to keep showing up. I was one of a few in my guild pushing to do the achievements so I only have myself to blame.
Trying to obtain more achievement points also caused me to fall back into the habit of playing more than I should, but the shorter raid schedule and limiting my alt(s) time actually caused me to play less than I have in the past.
Most of my gripes stem from how I play the game, not the game itself. The two complaints I have Blizzard has actually committed to not repeating.
1) "Yeah, but can you do *this*?" If 25-man is supposed to be the more difficult raid, make it so. Don't have a 10-mannable dragon be the apex. Or tell us in advance that's the case. Blizzard has admitted that making the 10-man Sartharion + 3 Drakes harder than the 25 was a mistake.
2) "Limited time only" I understand the developers wanting to keep accomplishments special by not allowing raiders to get some achievements after a certain time, but once again can we get more advanced notice? A Blue made a small post advising anyone wanting the new proto-drakes that they will have a restricted time to get them.
Interestingly enough, my plans for 3.1 will make my gripes moot even if Blizzard hadn't corrected things for future raids:
1) I'm sticking to doing only one raid type, either 10 or 25. Probably 25. 25-man raids allow for more flexibility. A 10-man group will inevitably be unable to raid if 2 people don't show up. A 25-man doesn't have that problem. If I'm one of the two absentees (not that I ever have bad attendance), I'd feel worse about it in the 10-man group.
2) I'm not going to break my neck trying to get achievements any more. At least not the ones that require you to depend on others. Yes, this is an MMO, and playing with others is the whole point. However unless everyone is working toward the same goal you are in for a World...of Warcraft disappointment. Growing jealous of the players who didn't seem to care made me question why I was going above and beyond what was fun to get them for myself.
So there's my look back.
I have gripes about 3.1 as a resto druid, but since I haven't played on the PTR they could very well be unfounded. And why start a patch with a bunch of gripes when I just ended one with so few.
See you in Ulduar!