The latest version of the K1 looks to be pretty good in fastfire mode if the AoA video on youtube is anything to go by.
The latest version is GEN 5 and that is the one they reviewed and the one I've used. The youtube video done by Matt comparing the FX Impact with the Huben certainly doesn't use the latest version of the Huben . I'm certainly not claiming that the Huben is better than the FX Impact because I don't think it is.
My friend who owns both certainly prefers the FX.
My basic problem with the Steyr is simply the price. I cannot get my head around an air rifle in current production costing over £2500 when I could buy an Edgun Matador R5M-which to me is the very best bullpup on the market- for about a grand less. OK if you MUST have a semi auto/self indexing rifle then your choice is very limited especially if you are restricted to 12 ft lb.