I never saw the old version, can't believe it just so simple back in the day

I thought you reorganize everything to make it looks cleaner.
As a Java developer myself I can definitely see the appeal of using Swing but JavaFX would definitely give the CAT more professional looking, in my opinion.
It just a thought anyway.
Well i first released 20 Beta Version and 46 Official version.
Every CAT Version have some add-ons : parameters, log, improvements. So, early CAT version could seems easier at GUI level, but every CAT version is more power than the previous one :-)
I think CAT is clean, but of course i need to put parameters/log/table somewhere : have 3 parameters 1 log and 5 table is different than have 60 parameters, 3 logs and 10 table.
About JavaFX well i'm not sure about the improvements i could get. At Swing level there'a lot of support and code example....