I've have experience of these props.
When in the States last year I thought I purchased a 13.25x17" genuine Yam prop from a localish dealer (for a Yam 80 2 stroke). In the end I couldn't pick this prop up myself (work commitments) so I got em to mail it to my hotel, it turned up and wasn't a Yam prop at all but a Michigan "Match" one. I phoned the shop and was told this was the only type of prop they had available. I was going home the next day and as I only payed $115 (£70) I figured that if it was no good I'd get rid of the thing for the same price. So I bought it home.
Fitted the prop in place of a Stainless steel one of the same dimentions and lost 1 knott top end and wasn't noticable in acceleration and grip. It did raise the rpm by 400 which was the desired effect.
Anyway I purchased a newer motor in Feb (Merc 90 fourstroke) this came with a 15" prop, so it was well under propped. Fitted the Michigan and away I went.
Two weeks ago I had the opportunaty to test a couple of Stainless ones, with a view to buy.
One SS was a mercury vengence 16" pitch and the other was a Solas 13.25x17 the same as dimentions as the Michigan (alloy).
Top end with the Solas was the same as the Alloy Michigan, couldn't really tell any difference in high speed handling, but cruising speed at 4000rpm was up from 25 knotts to 29 knotts.
To sum up:
I couldn't justify buying a SS prop as the performance gains over the Michigan were negligable, I'm very happy with my Michigan Match prop and consider it's performance to be on par with a Stainless one.
I would buy one again based upon the experience I have.
Why don't you phone the dealer and ask them if you can trial the prop on the condition that if it isn't suitable they'll give you a genuine replacement or refund your moneys.
Hope the above info helps.