To start with the last question first -- I should say that I am a very casual player who used to play DDO a LOT but now play increasingly less and less, mostly due to changes in the game that started with the addition of the Guild Reknown/BraveryBonus system that, when combined, made the game a lot less friendly (I think) for solo casual players. That is my major pet peeve. Because XP is at such a premium, partially because the end game shifted toward multiple TRs on each character, people seemed to be much less willing to group with others outside their immediate circles.
Another pet peeve is the crafting system that you came up with. I simply don't have the mental energy to figure it out and I don't see why it was made so complicated. The items you can make from it don't seem worth the effort and the components just add more clutter to an already cluttered inventory. So, I've ignored it.
For the Enhancements: The trees seemed like a clearer more intuitive interface, which would be an improvement, but the actual content of the trees that I've seen simply didn't seem sensible to me. Since I'm not a 'build' guy, it doesn't bother me that my current characters might become so-called 'broken,' but I'd still want to be able to make choices that allow me to create something equally fun, and I'm not convinced this will be the case so far.
Guild Decay: I think you have to decide if you can live in a world where every guild eventually reaches level 100 with all of the benefits. I actually understand why decay was put in, but it seems to make a lot of people unhappy. I think the game was just fine before Guildships and the hooks and everything were in the game and it wouldn't bother me if that was all taken out of the game.
Oh yea, and the new forums are pretty horrible. I'm much less inclined to come here and read, much less post.