I catch myself spinning 35 inch tires on my Gladiator all the time. Granted it's got 4.11s in it. I'm guessing your rental doesn't have the max tow with lower gears.
The Gladiator JT soft top is really quiet. We had a soft top on our JKU too. We regularly drive from Colorado to Kansas and it's always windy. We've taken the JKU and the Gladiator multiple times. WAY quieter in the Gladiator. Not sure why but it certainly is.