Personally, I would go with the Rena XP series over the Fluval. I had one of the older Fluvals on my 90 gallon tank, and one f the locking clips on the lid broke fairly soon after I bought it. I know they have redesigned much of the filter since then, so that may not be an issue now. The Rena has been a great filter- easy to set up, maintain and super quiet. I also have a Classic Eheim on my 55 gallon tank. It's also a good filter, tho it can be a bit of a pain to deal with. But, as stated above, what is a pain to one person is likely to be no big deal to another. I would recommend the XP filters to anyone, tho.