Correction - My SS is 111.6MPH. 

Typically a lower lofted head will yield a lower spin rate. My guess would be he put you in the lower lofted head to help keep the spin down and in return give you more roll out. I could be way though, your best bet would be to ask, most fitters love to talk technical nonsense with players.

If your miss is a fade than that would make sense because when you make the loft higher it actually shuts the face a little bit because of the lie angle.

Scott K

I was recently fitted for a 913 D2 Driver.  The club fitter was great and fitted me into a 9.5 Degree...adjusted to 11 Degree (A4).   My launch numbers were great...however on the course I find my launch angle low.   I have historically hit a 12 degree due to a negative AoA.   My question is this.....why would he choose a 9.5 adjusted to 11 vs. a 10.5 adjusted to 11?  Or a 12 adjusted to 11.25?  I guess what I am wondering.  All things being equal.....what is the difference between two heads...9.5 or 10.5 ...both being adjusted to 11?  Spin?   I am thinking of adding a 12 so I have more range in the upper lofts....but worried that due to my fitting numbers...it would have too much spin.  My SS was 11.6 mph. 

Help?

The 9.5* in the A4 position is + 1.5*, which would make it a perfect 11*. The other 2 lofts you mentioned, can only make it to 11.25*. You'd be suprised about how much just that .25* would affect spin. Which shaft were you fit in to? What was your ball speed/launch angle, etc., from the fitting?