Thanks for the answers guys!
To me, the cab is one of the most important parts to achieve a great guitar sound (if not the most) and that's where the profiler shines. It captures the summing parts of the chain in a very accurate way.
I think using a guitar cab with it is an absolute error. Haven't you noticed that profiles sound very similar to each other (in the same gain range) when using the same -phisical- cab?
IMO using a cab ruins the whole purpose of the profiler. Even worst, if you monitorize your sound through a cab, your sound will be absolutely different as the one sent to FOH. How would you rely on that?
Of course, the story changes if you profile your own amp + cab and use a merged profile. But that's not the situation I am talking about and unless there's a good turnaround for cabs (eq... whathever), I think FRFR is definitely the best solution for live purposes.