indeed - you can download a trial - which is on a month trial I think.
use a regular expression rule of .*Script Version.*
This will then ignore the script version line that Rick adds to the top of every file that changes with each release.
Essentially once you run this rule on all files both within the latest release and on your site, you should be left with just the files that either you or Rick has altered on each upgrade. it is then just a case of importing your changes into the ricks files and upload. If you have marked your changes then it should be nice and quick.
When you scroll through each file that has differences remaining it is usually fairly easy to see which files you have altered.
In minor releases i.e. 7.1.1 then the changes made by Rick are probably going to be small and hopefully all current mods should work.
I think upgrading to 7.1 took me no more than 10 minutes or so once I had a fresh copy of my site on my PC.
at the moment - but expanding all the time....) 
