I have not noticed any difference in how dry my face is between different soaps as long as I am using a post shave moisturizer, but maybe my idea of a soap that dries out your skin is different than yours. What are some soaps that you consider drying and which do you find to be moisturizing? With regard to Rud's reviews I was surprised to hear him say that WSP Formula T was sub-par in moisturizing ability. I don't find that my skin feels any different after using WSP vs. Barrister & Mann or MWF.I find post-shave pretty important for my criteria. One thing that relates to post-shave tends to be residual slickness. If it dries out my skin, the chances are that it won't have much residual slickness.
The reason for my emphasis on post-shave is that it'll help even more with the added splash/balm. If a soap has a good post-shave feature, the balm will have a better effect on my skin. However, if the soap dries out my skin, the balm has to work harder to re-moisturize the skin and the end result is average. I think it's better to prevent skin from drying out so that the balms have less to work on and just add to the nourishing properties. I know this is not a popular opinion but that's my stance on it after couple years of trying drying and moisturizing soaps.