For me, version 2.7 has really delivered. The integration with SONAR is now tight, and a lot of bugs have been fixed. This program was always fantastic value and well supported by nice people. Now I think it is really there. Disk streaming is a useful feature, although memory is so cheap now I'm not sure I'll actually bother with it - I have 512MB.
What is great is that the Akai S5000-S6000 is now fixed, so that if you want an awful lot of great banks to play with, and you have a fast internet connection, you should visit: