One complaint I've noticed is that the guild quests (and by that I do mean to include the College, Companions, and Brotherhood, I'm just going to stick to "guilds" for brevity's sake) are somewhat lacking. I've heard complaints that they're too short or too shallow, and from what I've accompished so far I'm not so sure I agree. Admittedly, playing through the mage quests and the companion quests I was a little non-plussed, but then I went back to the mage quests with another character and actually did the mini quests before completing the "main" mage quest. What I found that there were actually quite a few mini quests available, with almost every NPC in the college able to give you at least one. I found that upon doing these first I ended up feeling like the experience was a lot more like the guillds in the previous games. I then realized why (possibly) people are complaining about the brevity of the guild quests.

In the previous games the player had to go through a crapton of busy work to advance the story attatched to the guild. In fact, in Morrowind it could be all busy work and no story at all (at least in the mage's guild). Even in Oblivion, where all the guilds had really strong stories, there were still filler quests you had to deal with. In the Mages Guild it was the recomendations, in the Thieves Guild it was fencing goods, et cetera. The difference was that you had to do that filler stuff to advance in rank and advance the story. In Skyrim, at least with the Mages College and the Companions, you have to do little if any of the busy work, you can push right through the main part and skip over the rest. I have no idea what other player's experiences are exactly, but I wonder if the dissatisfaction with certain guild quests is due to the lack of barriers forcing the player to slow down during the guild quests.

Personally, I think this feature is fantastic. It let's you get an uninterrupted story, and the extra stuff is still there, if you take the time to look for it and do it. To be honest, I get the feeling that a lot of the complaints about this game (apart from glitches and performance issues) stem from players that fly through the game uninhibited and wonder why it wasn't satisfying when they never stopped to smell the roses (figuratively speaking of course. See, that's the mark of a good game, when I actually have to make that distinction). But maybe that's just my opinion. I should also mention that I have not yet completed the Brotherhood or Thieves Guild quests, so maybe there's something I'm missing, guess I'll just have to see.

Been saying this for a while now, if you do the guild side quests during the guild main quest it feels proper.