I have a rena xp3 for my 100 gal. Its alright, not that great. It says its enough for a 185 gallon. But to me it seems as if it can barely keep my water clean.
the xps are more for biomedia if anything, the gallon rating or whatever isnt near what its supposed to be. ac110 are pretty good, i know they arent canisters but they are cheaper and have a pretty good amount of media
i have a 100 gallon with a sump and rena xp4,the xp4 is ok but not the best,if u really wanna save money ther is so many options thers diy sumps that are pretty easy are ac110 and the odysea canisters ther pretty good for the money u spend