I had the 4.30 and it towed great. Replaced with a 4.10 in the RAM. I always buy the largest gears available since the primary duty of the truck is to tow (though it is also a daily driver).
With the 4.30 I always wondered how much I could have saved on fuel had I gone with the 3.73. Now had I gone with the 3.73 I'd have been wondering how much better the towing etc experience would be if I'd have gone with the 4.30. In the end it's worth more to me to have the "best" tow experience I can, others may feel different.