i rolled 4.10s on my 05 GT DD and loved it. you'll rev a little higher on the interstate (and so, burn a lil more gas), but other than that, there's no down-side. you definitely will
not be stuck at the speed. i drove from az to fl and never went below 90. you'll def love on-ramps; 0-90 in no time
. only problem is, i drove a 2010 gt w/ the stock gears, and it felt neutered.