Agree with all the opinions suggested here.
My experience with the Maverick, Wildcat MKIII and Impact's (MKI, MKII, M3), would share the same evaluation as you all.
I have chosen the Impacts' to be my choice for reasons I will describe, as the Maverick and Wildcat MKIII are gone.
The Wildcat MKIII and Maverick were intriguing at the time for their interchangeable platforms with liners and probs. The Maverick had the "New Dual Regulators" set in a close too Impact platform. What could be better!!!...Well, after I got an Impact MKII and M3, I began to understand why the Impact was superior in my mind. Two main design features that set the Impact apart from the Maverick and Wildcat was the shot cycle and the harmonic balance. For me, it was the difference between "great everyday airguns" and a "precision air rifle". The FX Impact, regardless of how many O-rings it has, is superior in its platform and performance compared to each of the others. FX has designed each of them to fit a performance and price point exactly as intended and I have no complaints, they are all wonderful.
Patrick