To me, Trumper's shaving soaps seem to be custom-made for SR shaving. The skin does not get too slippery, so stretching the skin for the razor is easier than with most other soaps. The slipperiness of Colonel Conk works better for DE razor shaving though. The Trumper soaps also foam up to produce a nice lather very quickly, and the skin feels nice afterward. For SR shaving I have found nothing better. Trumper's soaps also smell very good (the rose soap is a favorite of many people)

I think Colonel Conk is very good at a much cheaper price. I have yet to check out Gentlemen's Quarter, though.