Rekster
Experienced
First of all welcome to the Fractal family! This is a really good community so feel free to as any questions.
As for your options, especially if you come from a long tube amp background I highly recommend the 2:90 route. That power amp (the best power amp by the way!) will make the Axe-Fx III sound and feel just like a real tube amp with real cabinets. Solid state and FRFR is where I feel people have the most difficulties adjusting even when it might be more convenient.
Do you have any experience with the 2:50 vs the 2:90 and the Axe FX III? I'm still undecided as to what I want to do but if I went tube I'm curious if the 2:50 would be sufficient.