To expand a bit on my earlier optimism:
Yes, I am having fun in the beta. The UI lag bothers me but I expect this to be fixed or at least not near as bad as it is now by the time things go live. If the UI lag is as bad as it is now when the game goes live they are going to have major problems.
The lack of AH or any method of auto-searching through the retainer "slums" bothers me. It's not a game breaker for me, and I'm hopeful that they will eventually add something of the sort to the game after launch although I might be deluding myself.
I'm honestly glad that there are 48 hour timers on the guildleves. That gives me time to do other things rather than always feeling like I have to do my guildleves for the day. Between work and house upkeep I have enough jobs to do, I don't need more jobs in the game I'm playing.
No hardware mouse doesn't really bother me. I'm currently not seeing that much mouse lag. Admittedly if I try to turn on AA, AO or DoF, forget it, mouse controls are out the window, but without those on the keyboard and mouse controls are mostly fine.
Do I think the UI is perfect? Nope. I feel that I'm going to have to macro a ton of stuff to make it usable. I'm glad that we have the ability to macro things, but not being able to customize hotkeys is annoying and not being able to open up multiple windows to compare things is also annoying. I really want to be able to open up my inventory or ability panel while I'm customizing macros so that I don't have to write down the exact spelling of everything. It usually takes me 2 or 3 iterations of macro editing before I get everything right. The UI is probably my biggest complaint right now and I'm not expecting anywhere near all my complaints to be addressed at launch. I fully expect that I'm going to have to work around and against the UI as much as the UI will assist me playing the game.
So I'm having fun in beta exploring, fighting, doing guildleves, harvesting and crafting. I specifically am avoiding doing the main quest lines for now since I want to save those for retail (I did a couple of the steps and they were awesome). I really love the fact that not everyone and everything has a stupid quest marker or vendor sign over their head. I enjoy the fact that not everything is marked on the minimap. Removing these "helpers" is actually making me pay attention to the game and helping my immersion rather than feeling like I'm playing the game on the minimap.