My tl;dr version (the Progress was the first DE razor I bought when I started traditional shaving 8+ years ago; I owned the Ambassador for ~5 weeks recently & sold it):
For my face, Ambassador had more blade feel at every given setting.
--Progress significant blade chatter compared to the Ambassador
--Fit & finish was no comparison, IMO. Ambassador wins hands down, as it should when priced ~3.5x a new Progress
--Ambassador handle knurling is the best I have ever (and suspect ever will) experience; never cared for the Progress (lack of) grippiness, personally, YMMV of course
I know, very superficial take from me, but I'm not good at reviews and such.
I ultimately sold the Ambassador because it wasn't a razor that I found smooth, and smoothness is my touchstone as someone who shaves 6x/week the vast majority of weeks. I mean, my attitude is I can use any mechanically sound DE as a daily. It's about whether I WANT to; whether it's a razor I feel almost compelled to use, drawn to daily.
With a small discount I got from Razor Emporium here in the U.S. (10%), and factoring in Paypal & shipping fees I ate when selling, I figure it cost me ~$55USD to trial the Ambassador for those 5 weeks. I don't have regret about that, because I needed to know; I have a thing for adjustables, and the design sensibilities of the Ambassador has been calling to me since I first learned it was in development, but I just simply was away from the shaving game during the ~18 month stretch it was first out. I wouldn't want to have a trial expense of this sort every month, but as part of the "hobby" (don't really care for this term, but can't think of an alternative), I am fine with such an expense occasionally.
Cost/performance ratio is so subjective, Hopefully you can find a way to borrow one to try, or are willing to buy kinda blind and offload for a small loss if it doesn't meet your needs.