all I can add is that having ridden loaded on dirt roads a fair amount lately, but with Supremes 2in slicks, regular Marathons 1.5in and various 28mm slicks in the past, first of all, going as wide as you can is clearly the better route. My 2in supremes measure out narrower, to only 45mm, but even with them, lower pressures make a real diff in how they ride over looser surfaces, and while you cant go wider than 2in, at least even the Mondial has significant side tread compared to the supremes.
I guess only you know what sort of dirt roads you'll be on, and how comfortable you are on various surfaces from a bike handling side of things.
It seems that the additional tread depth and pattern of the 365 cmopared to the Mondials is not that much, and my personal opinion and experience is that using a lighter tire is always going to have an advantage that you feel in the ride of the bike--and to me would offset the slight knobbier aspect of the 365s.--but just one persons opinion and who hasnt ridden on the 365's....
another thing I dont know about is how both these tires compare sidewall wise, stiffness. I imagine they are similar, as both are super tough tires, but a really tough stiff sidewall tire will always ride more harshly than another one with more flexible sidewalls., especially at lower pressures.
Its too bad you cant use wider tires, Ive ridden a bit on 2.5in Extraterrestrials, and a friend used them doing a large part of the Divide trail last summer, with two rear panniers and one front pannier, and they worked very well--the added width and lower pressure really works well on a wide variety of surfaces.
good luck with your decision
I guess they're ok. I us 38s for commuting and rail trails. I did get a piece of glass stuck in them once. They're easy to get on and off the rims. I would recommend them. I run them at least 60 psi.