Yes! I've had my Tunze 9010 for about 6 months. It produces about a cup of wet skim daily in my 75-gallon reef tank with a 29-gallon sump.
If you want dryer skim, there is the 9015 collection cup ($105.52). Currently, I am trying to dial-in my new foam extraction unit ($95.28).
The Tunze can be configured for either in-tank or in-sump modes. The support on Reef Central Tunze USA forum is excellent with Roger Vitko of Tunze answering virtually every thread.
The reports of problems that I have read deal mostly with incorrect configurations. The Tunze comes with parts for both in-tank and in-sump modes. If the parts are intermixed, the skimmer will not work. The skimmer can be suspended with a bracket or magnet in the in-tank mode but must rest on a firm surface in the sump to seal the bottom plate.
It would be hard to find a better skimmer with its combination of small size, flexibility, quiet operation, and vendor support.