The Fox lineup is well thought of by the few bassoonists that I know these days. Multiple models with different key work. Hell, you can even get them with a French bell, if you want - my close friend Jim owns one and gets comments whenever he shows up in a new situation where the 'ivory' Heckel one is the norm.
I've played the Selmer horns (which are probably built for them by someone else), and all I can say is "meh".
More than that, my boy, who was an ace on the bassoon before playing music in Houston got in the way of ice hockey (and has since taken the horn up again), tried one out once. It was an apparent stolen horn (from some of the signs visible on the horn), but he said that it was like blowing into a tube full of damp socks - not a symphonic assessment, but about what I thought as well.
We used to live next door to the former principal bassoonist from the Tulsa Symphony. She taught my son for four years, and knew the horn inside and out. But, they moved away and we've lost touch over the years. And, my friend Jim is primarily a sax player for the past thirty years, so he probably would limit his opinion to the Fox horns.
There a bassoonfandom website somewhere. You could get a plethora of opinions there. And, when it comes time to make a decision, bring plenty of money...