I've tried a couple of rinseless washes. Here my impressions:
Blackfire Rinseless - tried this for the first time this weekend, and I'm liking it (which is good, since I bought a gallon of product). The towel glides on the paint when I'm washing the car, dries very evenly, and leaves a nice gloss and added slickness to the paint.
ONR with Wax: Been using this for about three months. The scent is great, cleans well, and again, leaves a slick finish behind - works well with my carnauba waxes. The Blackfire does seem to glide smoother while washing, though.
UWW+: Used this several times as a rinseless - cleans very well, and leaves a slick finish with some added shine.
ONR v2: The previous version of ONR. Ok product, good cleaning, but not as slick as the competition, nor does it leave as glossy a finish. ONR v3 has supposedly rectified these issues, but I have not yet tried my bottle to actually see if this is the case.
DP Rinseless (old version): So apparently this product has been improved recently, which is a good thing, as it was being left behind. A tad slicker finish than ONR v2, but it doesn't clean quite as well, and it also streaks a bit more than the other rinseless washes I've used. Bought this on BOGO - sold one bottle off, have used about a third of the other one, and I'm thinking that the remaining 2/3 might just end up sitting in the back of my cabinet forever.
I'm interested in trying the Pinnacle, Meguiar's and Dodo Juice ones - those will have to wait though, what with almost two gallons of product that I need to go through first...