The Achilles heel, IMHO, is the tire and axle capacity of the rear axle on a 2500 Sprinter when towing.
When we were looking for a Class B some years ago, the 3500 Sprinter was not being used yet by any "upfitters". So, our search was limited to Sprinter, Ford and Chevrolet (the Dodges were no longer be "upfitted").
We did want to tow regularly as we wanted to take both a motorcycle and a canoe with us. The motorcycle was inside the trailer, the canoe on top. The trailer was a single axle 3500 GVWR trailer.
When I did the arithmetic of adding the trailer tongue weight to the rear axle of the 2500 Sprinter, we would be WAAAAAAYYYYY overweight. So, no sprinter.
The wheelbase of the Chevrolet was much longer than the Ford, so the distance from the rear axle to the ball was MUCH shorter (about 17 inches shorter as I recall) on the Chevrolet, so we settled on a Chevrolet chassis.
In the end, we bought a new Pleasureway Lexor on a Chevrolet Express 3500 and have been VERY happy with it. We've towed well over 30,000 miles with nary a problem.
We did add an aux transmission cooler with fans, independent air bags on the rear axle, brake controller, and more.
AsheGuy's "local" towing of a small utility trailer with some mulch would not be a problem I'd think; but a long trip - up and down mountains etc. - well, I wouldn't want to do that in a Sprinter 2500 towing a 3,500 lb. trailer.
But, to each their own.