I switched to the 300EL tune, unhooked from the trailer and was able to muster out 16.5mpg with mixed DD'ing. Plenty of power, and smooth shifting, smokes a little more than I was hoping for if you lug down in OD, deffinately not excessive...just more than I've been used to with lower tunes.
Hooked back up to my trailer, 4k lbs (mostly empty), for a 150 miles or so... and was brought brought back down to 14.6mpg with more mixed DD'ing.
Trans seems to be shifting much better with the higher tune, even with trailer attached. However, I haven't tried using tow/haul. I noticed tow/haul seemed to only assist with downshifting, is there any other function?
Hopefully with an actual load while towing, the 300+ tunes aren't "too much". I've been enjoying driving around with little to no smoke compared to blacking out the street with my old 12v.
I'm gone for work now, so once I get back I'll play around with other tunes.