At first I hated the new UI but it is growing on me.
So far the only real Bug I have run into is the chat bug which is well known and hopefully fixed in this patch.
The character creation page doesn't feel as intuitive as the old version, but that simply may be because I've been using the old one for the past 3 years and this is different therefore screwing with my head a little. I will play with that system more when the Romulan faction is out. I'll create one of each tac/engi/sci to test it out.