Pros: Accessories, Soundstage, Customer service
Cons: A little light on bass
I decided to purchase the new model UE 900s instead of the UE 900 because of some build quality changes and added accessories.
Packaging - The packaging is very nice and they fit a lot into the fairly small box. Everything is quite elegant looking
Accessories - There are tons of accessories. There are many sizes of silicon and foam eartips to choose from, including spares of each one. There are 2 different headphone cables (one with a mic and 3 button, one without), a hard carrying case, and some connector cleaning gel
Build quality - What UE has promised that it has improved the build quality, and going to a more unibody design, and that has been my impressions so far. I feel the build quality is better than the outgoing UE 900 model.
Sound - The sound is quite good. They have very good mids and highs, they are a bit light on the bass so know that if you like a little heavier bass with your IEMs.