I have two Steyr Pro X, and personally love them, I have had a Huben and it was okay, not as well made or as accurate but it's much cheaper and at least you have the fun aspect of semi auto.

The FAC AGT Vulcan would my next choice as the one I had was unbelievably accurate, but obviously single shot so not really comparable

Kalibrgun make some really well made and accurate stuff as well so well worth a look

I know people rave about the FX line up, but all the ones I have had have been awful, especially the impact, however they were all bought at the beginning of the guns releases so I am sure they have had most of the problems ironed out, once bitten twice shy though.

Andy