You'll not go far wrong with either tbh. If you just want a DEDICATED hft gun the HFT500 has a slight advantage but as a "do all" a .177 ultimate sporter is VERY hard to beat.
Rick Ardern. RIP mate, never ever forgotten!
Currently in stock........
Steyr LG100 x2, Ripley AR5S x3, hw77 x2, hw80 x2, hw100, hw97, hw98, Walther Dommie, Walther LGV, Stoeger x20s .22, Daystate mk4 in a custom laminate stock, Diana mod 50 + Gamo compact & Röhm twinmaster pistols