When we were downsizing from a 45' unit we looked at the Sprinters. Check them out thoroughly, because the apparent promise (at least for us) wasn't upheld when we checked more deeply.
The lack of storage space and (sometimes) a wet bath were a couple of problems for us. They test drove fairly well, but that was empty (never drove one loaded). Most also had generators that run off of propane, rather than diesel, and since we occasionally have need to run the genny for quite some time, even a diesel genny was limited in run time by the fuel on board. If we were strictly weekend, that might be OK, but that's not us. Finally, the thought of two or three rainy days cooped up in that little space put us off. I have a neighbor with a Sprinter and he is very happy with it, but they aren't gone long when they go RVing.
Ultimately we decided on our current 38' Newmar which, for us, has worked out well.
I had a sprinter/Mercedes class C, or super B as some call it, for a couple years. Loved it for cruising around the country spending a few days or a week in various places. As we settled down a bit and realized we wanted to spend at least 2 weeks at a time in remote boondock sites the small size became a liability rather than an asset.
We now have a 25? trailer with opposing slides(lots of living space) and huge holding tanks so we can sit in one place for up to 3 weeks.
Thank you all for your comments. I am also concerned about lack of space and some manufacturers are better at creating space than others. While I think I can pare down all the "stuff" I feel it necessary to lug around, I am very concerned about the small space in general. We like to travel at least 3 times/year and 4 if we can and usually each trip works out to be 4 weeks or so. While the better fuel mileage is attractive, I'm just not sure being in such a small space for that long will be tolerable...much as I have read noted here.
Again, thanks for your comments and insight!!