I think you made the right choice. I guess you saw my other post comparing the two. The short answer for me is that the 4.30 wins ... if you tow enough to care about acceleration performance and you don't do lots of unloaded highway miles.

If you do care about highway unloaded mileage, 3.73 is better and as has been mentioned, 3.73 in 5th essentially equals 4.30 in 6th for steady state running on the highway so you don't lose really anything in towing highway cruising.

I have a similar commute and towing situation and the 4.30 is what I'll be looking for when the time comes.