I've found the rena xp filters to be quite cost effective and reliable. I have 3 XP2s, 2 XP3's and an XP4. I pretty much took the approach of "pick one and stick with it". I have found that to be good - it allows me to easily change filters without having to move hoses, etc. I suspect you will get a similar advantage if you go with any one of those filter lines.
When I first started buying them, they were pretty cheap, but lately they are not considerably cheaper than the others.