They’ve tweaked it a bit. Gone is the buggy Rapid UI and all of the brush icons have been replaced with far more descriptive icons. Z Mapper and multi displacement are back in and working, and although it looks generally similar at first glance it does seem to be cleaner and slicker all round. They also have included presets for different processes
Well I hang around the zbrush forums and complaints abound about the 3.1 realise, still buggy as hell apparently, still crashes, tho it seems to be 50/50 with alot of people not experiencing problems and alot people experiencing problems.
Hold off as long as you can JohnMonkey, see what happens now that Autodesk own Mudbox. Mudbox 2 will feature the chameleon paint engine, which should tackle some of the criticisms levelled at it so far.