I have a Finnex M tank (in storage atm). When I had it running I loved it. The design is really nice but I did add another small pump to increase water movement. The only thing I didn't like about it was the fact that it is made from acrylic (a positive in some people's book but not in mine). I liked the design so much I bought it despite the fact it is acrylic. There is also a model now with a refugium built in, wish I had that one instead looks sweet (but I don't think that one has a skimmer).
Plenums and ultra deep sand beds > all other setups!