I have a 2000 John Deere 4700 with 1250 hours on it and a 2002 Duramax with 110k on it. I'm the original owner of both. Have never used any additives in either, and have never had any issues whatsoever.
I live in VA and it can get quite cold in the winter, but not really for extended periods. I tend to buy all my diesel from the local BP station, and he does have an off-road pump. Of course on long trips, I'll fuel the Duramax from whatever stations I find along the way.
I just sold the 4700 and am getting a 5085M. I wasn't planning to begin using additives given my past positive experience, but I do sometimes ask myself if I'm pushing my luck or not?
With ultra low sulfer, a lube is needed but you will not see any issues until you do UOA.