There is an on-board sequencer, but it is cumbersome and much less preferable to computers. Other great features include a built-in mixer screen to balance the 16 parts. Some instruments are very good, including some brass, reeds, and horns. Others are so-so. The piano is pretty good, but I have found a better one on the new Alesis QS series.
Guitars are very good, as are basses.
Drums are VERY realistic. On-board effects are very nice. The keyboard doesn't react all that well, though. I think that the oversampling could have been much better. The Acoustic Modelling feature seems like it could be fun, but I didn't find much use for it.