I had no real problems with my Tunze 9002 but the Euro Reef NS nano skimmer totally kicked it's butt & cost not a lot more (around $155 Tunze vs. $180 Euro Reef if I remember correctly).
The only issue I had was the impellor disintegrating after a while but the new ones are supposed to last much longer.
The Biocube version will require you to have an open back chamber to accommodate as it sticks up a good few inches.
Euro Reef are no longer around but the nano skimmers are made by Nano Reef Systems.
Here's a
Link to their website.
I got mine from
Ocean Aquatics.
.