Apwsearch pretty much summed it up.
Core gets a good beating and especially outside geared lifting, forgetting the thighs is not a good idea.
The Westside protocol which was brought up earlier in this thread might not include that much front squat training, but they do have the SS-Bar (safety squat bar) in a very frequent use.
Squatting with that bar has a pretty similar effect to the FS, it's excellent for hammering the core and getting your hips open, while giving shoulders and elbows some rest.
I train purely for PL'ing and I cannot do heavy back squat work and bench at the same time (behind the neck work aggravates my left biceps tendon and the RC to some extent), so while on a bench priority cycle... it's only front squats and SS-b squats for me and my core sure as hell holds when moving back to back squats again. It's all about the belly.
Oh, and i also use the BB style FS... just keep the elbows high and don't stare your toes at mirror
My first post here, phew... goodbye virginity.