I have an Eheim 2075 pro III and it is a great filter. It isn't noticeably better than Rena XP3 for $100 less though.
My 2075 is the only canister filter I still use after switching to sumps. I use it as a backup to my sump. The only reason I still use the 2075 instead of the XP3 is because I spent so darned much on the 2075 that I have a hard time shelving it!
You can't go wrong with the Eheim... if you don't mind spending the extra money.
P.S. I can never figure out their numbering either. Half the time I can't even remember the number of the filter I have.