What you likely heard at Axpona was a combination of a bad room (the sound in almost every room was pretty bad), and more importantly, they were using ARC (Anthem Room Correction) all the way up to 5000hz. That simply leans any speaker out way too much unless you know how to limit the frequency range that the room correction effects (ideally have it stop at 300hz max) and also bump up the default room gain anthem sets.
I’ve heard the 3F sound great with the STR preamp and amp, but they will definitely sound even better with different gear, if you have the budget.