Pretty much comes down to that. I learned fronts before 5s but I've crashed a much higher percentage of front flips than 5s. If you over rotate a 540, you can usually open up to land a washed out 600-something or take it to 7, if you under rotate, keep it at 360.
If you over rotate a front flip, you have about a millisecond of notice before you go over the handlebars. If you under rotate, man...that shin bang... For me, front flips are about timing since you can't really spot the landing.
Actually, now that I'm typing this, anyone feel like superman fronts are easier than regular fronts since you basically spot your landing til the end of the rotation? I've never tried a superman front.