A very basic difference I do not like in Capture One 4.0 compared to Capture One Pro 3.7 is the user interface. On 3.7 I found the actual workflow well laid out and easy to navigate, but on 4 I do not find it as easy.
Normally, updates improve colour options, curves etc, which is the case in 4, but, normally updates do not drastically change the look of the program.
Version 4 is a completely different program by way of user interface. I'll continue with the trial though to see if I can make it work for me.