I have a single case with 4.7:1 gears and would agree with the above on a couple of points
- reverse is too low most of the time with the 4.7's... I find myself shifting into 4hi a lot to reverse, which is actually too high of gearing
- loss of the stock low range... Forest roads, access roads, etc, it would be nice to have an 'in between' gearing rather than high or real low
- driveshaft angles suck with single case... maybe not so much if you rotate the knuckles or something?
Basically the more gearing options the better. more more MORE!