I suppose "ease of towing" can be defined in several ways. My feeling was that the term applies mainly to how much engine power is needed, thus the direction of my answer; mpg comparisons do reflect the wind resistance and the power consumption.
But "ease of towing" can be taken to mean other things. In terms of handling and lack of sway, when properly loaded there shouldn't be much difference between a 19' and a 17', although the 17' has a small bit of an edge there. In maneuverability around obstacles (gas pumps, etc.) and on narrow roads, the smaller trailer has an edge. In terms of suspension, opinions vary somewhat on torsion vs spring axles but the differences should not be large enough to really influence a buying decision IMO.
BTW, the Casita will hold an edge in resale value over a stick built TT. And it has no edge seams where walls and roof join, which reduces the number of potential leak points as the years pass.
Whatever you decide, we hope you'll stick around and share your travel & trailer questions and experiences with us.
GMW, thanks for posting those pics of the Milenco mirror. I hadn't seen that one before, and it looks useful! When the rubber straps on my strap-on mirrors give out (as they always do eventually), I think I might switch to the Milenco.
