Disclaimer: I haven't skied Xplore yet, but hope to this Southern winter. I have tried on and played with the Madshus boots though, and was surprised how supportive they were given the minimal appearing cuff.
T4s don't fit me especially well, and caused horrendous blisters on the last long tour, which I was forced to abandon partway. Switchbacks work pretty well, but if I was doing it again I'd go for the X2 for more power. I've also used the T2X, but hated these due to the way they resist flexing at the ankle. The quite similar appearing F3 has a tongue versus overlap liner which IME is much more comfy and fits better, plus the boot does way better with a fixed heel; I'm hoping to try it as a tele boot this winter.
For the last few years I've been mostly on AT for touring and (occasional) resort skiing, and have been happy with it except when significant amounts of walking have been needed, but then all ski boots are crap to walk in IME. The boots are lighter and more comfy than T4, have way more ROM and more control, plus everything is lighter than T4 + Switchback.
For flatter stuff I've been eyeing Xplore, but the big question IMO is how wide a ski will be edgeable in firmer conditions, which I just don't know. Here though I'd never consider an SB98 with leather or NNN-BC; Xplore is unknown but I can't imagine that wide a ski working okay with other non-plastic boots.