I've got one of the 120 ones - a Loadamat.
It seems easy enough to load, in fact with test films I've had no problems at all. The first one I tried to dev, it kinked while separating the backing paper
The fact that you've got to constantly turn the knob, and the fact that my other tank (Gepe) has an easyloader means I haven't tried it again. I keep meaning to though.
I have read that some people take them with them when the wish to develop "on the road", as no darkroom or changing bag is required. The Rondix (a variation of the 35mm one) looks like the best of the bunch, with a nice little winding crank.