I agree with WinAndLinux on this one, unless it offers something that I really need JetClean (or any other cleaner) won't replace CCleaner on my PC.
I had a quick look at JetClean and my personal oppinion is that CCleaner cleans more temporary/junk files, especially if you consider the CCEnhancer tool provided by a third party. So I think it does this main job better. Although I am not a big fan of reg cleaning, CCleaner is considered safe. JetClean seems to be OK too and has the advantage of creating backups automatically (I wish CCleaner did this too). Both apps offer the ability to clean startup items but both pale in comparison to Autoruns. Both apps offer an unistaller and the one in JetClean is better organized, but there are other tools that can do this task better than both. I have no need for RAM Clean and Performance Booster but for some people these might come in handy.