Which Hoya did you get? They make some very good stuff. If you got a Pro1 or Super HMC/S-HMC you are going to be just fine.
The shots of the Great Ocean Road I did - the ones you really liked, those were shot with a Hoya Pro1 UV low profile in front of my 10-22. Honestly can't see a difference between a bare lens or my Schneider Optics B+W MRC filters (supposedly some of the very finest that you can get)
Most of my high end filters are B+W MRC, but I use some Hoya HMC and Pro1's on some lenses because they are already there and I can't tell a difference. Center sharpness on my 17-85 from 28mm-85mm, seen through a Hoya HMC, looks just like my 24-105, 724ISL, etc.etc.
I've also been staring at the world through Hoya's high end prescription optics for the last 5+ years.. and the world looks just fine (although the world is messed up in its own way
)