I agree with everything that has been said so far...when I first got a R7 Mini it was amazing how far I hit it but some drives with regular driver were 15-20 longer so I was in fairway with Mini and figured I should just play driver for the extra...then started to hit is wayward as i swing too much up on driver 7-9AOA and misses were penal...plus compared to some of the folks I play with who hit it 300 yards, my misses were not long enough to just wedge it onto the green..so not only was I loosing dispersion but still had long shots in. So I have decided to go back to hitting mini driver, accept the occasional shorter drives ( compared to best driver shots) and play from the shorter grass where I actually have a chance to hit more greens.
Some mini drivers shots were as long or longer than driver so the R7 mini is not short by any means. In addition, I have gone with a 5 wood and 7 wood and soon 9 wood as the 5 wood is so much more predictable to hit from fairway than even 3/4 woods and I rarely have to hit anything 3 wood length off the deck..in that case I should rather layup with iron.
The mini can also be hit off nice fluffy lie on fairway if needed..
In addition, I agree with sometimes larger heads with the gear effect can be harder to hit than smaller heads...same with blades vs big game improvement irons. I play better with blades partly because of thin sole but also less room on face to miss it..