I think that the right string, and more specifically tension, affects control more than head size. Also, the bigger the head size (apart from Rad OS), generally the stiffer the racquet. Smaller head sizes result in smaller sweet spots. If someone is having control problems with a "bigger" head size it's more than likely a string and tension issue. You can't string a larger racquet exactly like you string a smaller one and get the same results.
Even with an increase in head size, the increase is generally a very small percentage, though. At the end of the day, it's about what you personally like to hit with.
Trying to figure out what pros hit with is pointless for a couple of reasons:
1. They're usually playing with a highly modified version of whatever the claim is.
2. They play so much more tennis than anyone you know, and they are so much stronger than most people you know, that they can weild much heavier swingweights effectively. They also need the mass to absorb the massive pace that's being sent their way. (there are, of course, exceptions to this and every rule).
I think sometimes people do like to claim to love smaller and heavier racquets because it makes them feel like they are a better player. I've played with the PS 85 all the way to a 100 inch Babolat, and many in between. I currently play a BLX Blade 98...a happy marriage between the old school feel and new technology helping me generate pace with some control. It's what I like. My opinion.
Stick with your opinion...and more importantly what makes you play great, and you'll be just fine.
Wilson BLX Blade 98, CyberBlue. 4.5 all court singles and dubs.