Stock clubs at golf stores really only are the best fit for 10-20% of golfers.  So at best you have a 1 in 5 chance that a stock driver will work as well as your old driver.

I went to an opening event for the 913 drivers at a big box and I actually hit it longer than with my current driver.  ...After we took out the Bassara 50 g light flex and put in the Diamana Blue S+ regular flex.  My swing speed had improved from when I bought my last driver, so it had too much launch angle and spin.  The Blue and the 11 degree loft were about ideal.

Fitting matters.

I can relate to that.  My current driver is a TM 2007 Burner HT Draw (13*) with M flex shortened to 44.5".   Early last year I hit it alongside three R11 10.5 drivers (M flex , R flex and S flex) and it just smoked them (the S flex hit much straighter than the others but with a loss of distance -maybe 220 or so: I was hitting the 2K7 about 240-250 and probably about 230 with the other two).  I paid all of $69 for my current driver so it was further amplification to save my $400.  I've hit 270 yards on a couple occasions and greened a short par with this so-called "old man" driver.  Not changing it at this juncture because I am very consistent in my driving and pretty much find the center of the fairway; also have a few trick shots up my sleeve for the 200 yard par 3s (I do a full choke stinger shot).