So I had also ordered a Merkur Progress, as I wanted to try an adjustable DE as well. I paired it with an Astra SP blade, and I think it gave a good shave. But, I again went to the slant bar this morning, and it was closer. I have noticed that neither the Progress or the 37C slant give as aggressive a shave as the R41, but they are definitely more comfortable for day-to-day use.
Nick.