I had a Hoya 1B HMC Skylight before, which fulfilled its purpose when it broke over a pebble and saved my Sigma 30mm f/1.4 (mounted on a Canon 40d) when I dropped the bag (Soligor classic line M, which I until I opened it would've thought to be enough cushion to spare the glass, but alas...).
A pro photographer may have gripes over the spectral properties of this filter in comparison with a more expensive one, but it seems good enough for me (haven't noticed any bad influences at all on picture quality).
The fit (thread etc) is great and the build quality seems good so I'm a happy sailor.