Front drags normally have bigger washers, are smoother and are less likely to heat up under pressure from fish. They use big fixed spools for plenty of hard fighting fish offshore and are nearly all front drag.
I find front drag easier to use, reaching behind the reel feels clunky to me.
And for some reason, with rear drags I invariably turn the darned thing the wrong way at first (but that's probably just me).
I agree with the others. To me, front drag is way superior for fighting fast moving fish. Fiddling with a rear drag is more awkward mid-fight and I find front drags much smoother. I have a whole bunch of Shimano bait runner rear drag reels I have used for carp fishing but now seem to prefer just slackening off the front drag of other reels.
I use front drags for all my lure fishing. I dont use them because of the superior drag as lets be honest, we dont have many fish that are going to heat the washers to melting point! As long as the drag is smooth and not snatchy, thats fine. The thing I prefer is a Nick mentioned, with FD I feel like my contact is more direct, turn of the handle is immediately transferred to the spool, and the reel feels much more compact. With RD, it sometimes feel indirect in weird way. Maybe thats just me being strange!