Hi Peter,
3.5 is basically all the fixes available in the 3.0.x nightly build together with the new teststeps (JDBC and AMF), the SQL Query Builder (for JDBC-related functionality) and the JMS support. If you don't need those then the nightly build of 3.0.x is just as well. We will strive to fix bugs in both versions until 3.5 has gone final, after that 3.5 will be our priority..
Anyhow, running your existing projects through 3.5 just to help us catch any incompatibilities would be of great help, but I have full understanding if you don't have time or inclination.
regards!
/Ole
eviware.com