I also just recently replaced my Michelin XDS2's (245/70/r19.5) I loved the XDS2's....great ride, reltively quiet, awesome on hardpack and icy roads carrying my 19,000 truck load. I got about 70K miles on them. But this time they'd gone up even more in price and I expect I'll be doing a little more off-road and a little less interstate driving over the next 70K miles. So I also went over to the Hankook DH01's as I heard here from a poster who had used several different makes/models (lives on the west side of Mt Hood but can't remember who it was) that the DH01's do better offroad traction-wise than the XDS2's and were pretty comparable to the Toyos 608's (but chepaer by about $300.) Cost $2400 for 6 of them. Will probably sipe the middle of the tread on them for a little better ice traction but their sipe machine was down. Will do it on first rotation.
My rig is so different so as to make my comments useless to you, but I sure like the 19.5's. I would hate to lose the air-down options with 16's, but, I am more concerned with the weight carrying than the air-down capability so if I was borderline on capacities with a 16 I'd probably still go with 19.5's. We do our exploring into the rough stuff with our dirt bikes or Jeep so I don't need to go way off-road with the big rig.