Be careful Luggy, it takes a big man to admit when he's wrong.
I went about halfway through the list of top pros and nearly half use 100 s.i. heads. Over 75% use poly, mostly the Lux.
I guess the big question is when exactly did this major shift in head size and strings (i.e. the technology) take place. I thought it was within the past 20 years. Not prior to that, though it may have been available it was not in widespread use on the tour.
Ok, My perception was WRONG, according to that list which I don't how official it is because I found some inconsistencies; 30 players out of 68 uses a 100sq. I couldn't believe someone like Stepanek uses a 100sq for example.
I remember in 2008, Novak's racket came into discussion and it was mentioned he used a 93sq which I found it small. I know he changed rackets and then struggle for a bit but anyways, his racket looks smaller to me.
So yes, I was wrong........it seems that perhaps over 40% of the tour uses a 100sq.