Is it worth jumping in and getting the tried and tested Mach3 now, or wait until Mach4 is released and get the latest and greatest features ?

From the website, there's no upgrade path from 3 to 4 - which seems an, erm, brave decision on their part - so whatever I buy will be in use for the next few years.

It's to run an MV3 through a Gecko G540, so Mach3 has by far the largest user-base and knowledge-base.

Adrian.