based on experience I've had with my 2015 duramax, friends 2015 F250 diesel and another camper with a 2010 dodge cummins, it IMHO really boils down to which one YOU like driving and riding in BEST. ALL are very capable and reliable. My advice, take some test drives and then decide.
And, at least with GM, the 3500SRW and 2500HD are virtually identical pricing for the same trim level and options. So, if you can find a 3500SRW, I'd seriously consider it. Likely similar with ford and dodge.
We looked when we got our 2015 Denali, but while there were 2500HD's with options we wanted, the 3500SRW short box were pretty scarce so we ended up with the 2500HD.
