the only experience I have with reloading 50 BMG is with the Dillon BFR. Hands down a serious monster of a press and perfectly suited to the 50 BMG cartridge. Haven't tried the others, but I'd be a bit dubious about them. You're asking a lot from a press with cases this big, and requireing this much pressure in sizing ops. Wouldn't surprise me at all if running 50 BMG cases through a lighter press wound up springing or otherwise breaking them.
So far have reloaded roughly 400 rounds on it with no problem..... Can't give you a comparison since I don't have any experience with the other manufacturers......
Yep, It's pricey but if you shoot much it pays back pretty quick....
Brass prep for this caliber is a PITA.... FL sizing takes a man and a small boy so be sure and mount your press to something very solid.... Imperial sizing wax is your friend here and be sure to lube not only the outside of the case but the inside as well.... You will need to trim your brass just like any other bottle neck case since over repeated shots it will grow to the point where it won't chamber.... You also will need to ream the primer pocket to size if you want reasonable success in seating your primers.... The good news is once you prep your brass it will be easier for successive loads (until you reach the point where you need to stress relieve your brass necks).....