I like the fluval because I like internal filters allowing me to completely cover the tank (reduces rate of evaporation).
I've got the previous version of the Fulval internal filters. I like the idea of the new multi-stage filter because you are free to replace the physical filtration media while the biological pellets remain in place.
I haven't used any of these new c filters fro fluval, but I overall like the idea of them (well, other than their size... they are not tiny).