Mesa makes awesome stuff but their most popular amps are easy to misunderstand and as such, they can leave a lot of people with an awful first impression.
I love Marks, but they are are not intuitive to dial at all, mostly because their controls are horrendously labeled, even now. No, those three tone knobs shouldn't be called Bass, Middle, and Treble, because every guitar player in the universe understands the concept that standard tonestack controls go in the circuit after preamp distortion like they do on every other amp ever made. But not so on the Mark series, no sir! Instead they work like an EQ pedal you put in front of your amp. So what happens is players ignore the GEQ, thinking it's "extra" when it's every bit as vital as the tonestack on any other amp, and crank the Bass knob, thinking they'll get room-filling modern tone, but everything just flubs out because of all those lows being sent to the preamp gain stages. Then they walk away shaking their head and going back to their other amps.
I love Rectos too, but they're also not intuitive to use. They are universally understood to be high gain amps, but they use basically zero filtering in the preamp, which means none of the bloated low frequencies that kill clarity are filtered away, so if you use any gain at all, you get flubby tone. And no, turning the Bass knob down will not "tighten" a Recto, because the tonestack in Rectos are where they should be, after the preamp, after all the distortion has already been generated. Also, they are very dynamic amps, probably some of the most dynamic modern high gain amps available. This means that if you're not boosting them, they are flubby, mushy sounding amps with just about zero chug or slice unless you slam the strings with your right hand as hard as you can even with the gain up. If you don't boost them, it takes extremely tight and controlled playing to make them do what you'd want them to do. Using the right boost changes them completely into the idealized firebreathing benchmark high gain amp you want them to be, but most people aren't told that, and music stores usually don't have a line of OD pedals plugged in and ready to go in front of every Recto, so that's not how people try them out.
Once you learn how Mesa amps work and how to best use them though, they're very hard to beat. It sounds simple but it usually takes a long time for players to get there. It's just the nature of the search.