I'm still trying to figure this one out...I'm 6'3'' and in my 14 JKU I need to raise the seat to get proper line of sight. When the seat is cranked to the floor I have a foot of headroom and am sitting too low.
To chime in on the subject in general, my 14 JKU is my 2nd JK and my 6th Wrangler (YJ and TJ's) overall. I have an 11 and 14 year old that occupy the back seat frequently, occasionally a couple hundred pound dogs too. The JKU does everything great IMHO. I used to have a heavily modded TJ, a truck for towing and general DD stuff, and the wife's SUV for family hauling. One day I came to the realization that I love driving a Jeep every day and want one that will do everything in one package. JKU is totally it, reason I'm on my second one is that my 08 just didn't have the power and economy I wanted nor did it tow well enough. After looking at the powertrain upgrade with the pentastar and all the other optional amenities added in the newer JK's that make for a more pleasant DD it was a no-brainer. My new JKU rubicon is comfortable, capable, spacious for the family, tows enough, has ample power, and plenty comfortable for daily use.
Now the above is my 2 cents, so that and a quarter won't buy you a cheap cup of coffee anywhere!