I agree with Bill concerning his comments on the benefits of a software based arranger system. In addition you have the flexibility to use any wavetable or instrument samples you wish all the way up to the highest quality available today. Again these can be updated as improvements are implemented. Same holds true for other supporting software, e.g., vocal harmonizers, effects, etc. In other words any VST can be tied together with virtual midi cables and VST Hosts, e.g., forte, etc.

Plus you can use the Midi Controller of your choice (88 note, 76 note, 61 note, weighted or not and the features for controlling your software).

Plus I just simply like the overall elegant philosophy of a totally software based solution.

To make all this sound and operate well you need to pay attention to the computer and sound card your going to use. Plus it takes time to set it all up and make it work reliably.