Videos from PaulHFilms, RazorEmporium, Ruds Shaves, Kevy Shaves and Northern Shaver, plus various print articles all consider this. Basically, the Parker Variant improves upon issues of the Merkur Progress (introduced around 1955-56): non-knurled handle and dial, calibration issues (fixed on Mergress after-market razors), balance, blade grip, etc. Both provide a similar shave, but some subtle differences may sway you one way or the other. The long handle Merkur Progress variety is closer in length to the Parker Variant.
They are about the same measurements but the Model T gives more blade feel and aggressiveness simply due to the blade angle and safety bars being different. I would say that the numbers on the dial feel and shave like 0.5-1 more than the plates on the 6S/C
I get the feeling this guy hardly has any hair on his cheeks. Literally every single video of him he starts out looking what I look like after a shave.
That would be a great one if I owned an Ambassador. I may have already done this in the past though. You might want to search the videos on this channel or my old ilather channel.
This guy has a lot of experience but somehow has never learnt to do even a half decent lather. His lather is pasty and not a fluffy lather. He should learn as we all do from this guy: ”The master in lathering aka Another Cut Above”