If you Front Squat regularly you'll find that you can build big legs just fine. It places more emphasis on your Quadriceps, so at first you'll find that you won't be going as heavy as with your regular Squat. However, I know some lifters who have both lifts within 50lbs or so of each other, so it all depends on how often you're training them.
After my meet on the 26th I plan to put regular Squats aside as well and concentrate on Front Squats, Push-Presses, and Deadlifts as my primary movements. Guess we'll both figure it out. haha
Form follows function.