I hope, and expect, the Mustang to be as good as you say it is.
My first Corbin was bought in 1988 ( for a Transalp) and I have had three others since, all of which I found comfortable, especially the Gunfighter and Lady I had on my 900SS. They have always been expensive over here, but the price asked for the new G & L for the Scrambler is far too high.
Both the AA and I prefer the look of the Corbin, which is $452, as against $329 for the Mustang: I do not understand why I can buy the latter for under £300 (although delighted that I can) when the Corbin importer wants £525. I accept that premium products - and I put Corbin in that category - demand premium prices, but there are limits, when the sniff of overcharging is in the air.
In the meantime, when the weather improves and opportunity presents, I shall try my economical ( cheapskate, you call it ) option of riding the Classic wearing cycling gel shorts under my usual motorcycling trousers, as an alternative to a gel insert.