Thanks for the posts folks. You know I hadn't actually thought of the clamp on the chainstay deal as being nice for switching bikes. I have one of those, and two other trailers that have hitches that mount to the axle, and I DO find it annoying switching it between bikes or having to take it off a bike b/c I'm going to race it. Funny that never hit me till I just read it. So I suppose the trailer I reconfigure will be much less work than I figured.. leave it two wheeled (suits my purposes) and leave the clamp to chainstay hitch.
Thanks again