Two different drivers, two different results?

[dhatcher]

I realize people often want to blame equipment for poor shot making in golf.  Setting that aside, today I was at the practice range with my family (they golf too) and I took the opportunity to try my brother in-law's driver.  He's got a Callaway FT9 neutral, 10*, stiff shaft and my regular driver is a Taylormade Burner Superfast 2.0, 10.5*, regular shaft.

Since I've got the Taylormade (a couple months ago) my shots with it have been inconsistent at best.  Sometimes slice, sometimes draw, sometimes straight.  When I tried out his FT9 driver, I hit _every_ shot straight and longer than my Taylormade.  I almost purposely tried to hit the Callaway bad just to see and even when I thought I hit a "bad" shot it still wasn't terrible.

I wanted to get everyone's thoughts on why that might be?  I'm guessing it might be because of the stiff shaft versus regular shaft? I feel like I have a quick swing speed but, honestly, haven't ever had my driver swing speed measured.  I also noticed the loft is a half degree different but, I can't imagine that making much difference.

[mlf16507]

It could be the flex difference, weight difference, shaft flexing point or length.

[dhatcher]

I did notice the FT9 does feel quite a bit heavier than my Burner.  Thought that might have something to do with it as well.