i'm fine with my 3.21 and 33's
my highway driving dind't change at all sixth is exactly the same. it was never really good to begin with.... but its still the same

 

I pretty much like the stock gears and 35's on my X. Yes, it boggs down sometimes and would be nice to go where I want to go quicker but having gone on two trips recently with another Jeep with bigger gears and 35's, my gas mileage was awesome compared to his! I'll stay a liitle bugger awhile longer