Boom it's really great. So far the best palyer for IOS I tried.
However, I found important missing features (or maybe I need to set someting up?).
1. update play count - I found this useful since I have itunes playlist that refreshes based on when last some track was played
2. play locations in the track - very useful for podcasts to resume playing a track on last location
3. since you can access the iphone/ipad tracks, wonder if you access the audiobooks? The listening experience will definitely improve by listing them with Boom.