I have one pair of Sanders & Sanders, a pair of shoes that they made for E.T. Wright's "Master's Collection" (of which all of the English ones are made by S&S). It's not a bad shoe, but it certainly isn't C&J. The leathers aren't as nice, nor is the finishing, nor is the sole. I've seen several of their models, and like mine, they're a nice shoe but nothing that would stop traffic.
I'm assuming... hoping... that Polo is requiring special upgrades for their Polo models, because most Sanders shoes that I've seen run in the $200 range or so (my shoe is a canvas oxford and was about $180 retail). Thus, if Polo is expecting to get $595 for only-slightly-better S&S shoes, I think they will have lots of complaints.
S&S are excellent quality for their original retail price ($200 or so), are welted, and are certainly better than most "designer" type shoes, but they aren't at all comparative to my C&J's, whether regular grade or the hand grade... as evident in the price difference.