Unless you are some kind of kick a$$ rider, the bike will offer a very nice ride. Do not worry about the strength of the stays. As was mentioned elsewhere, they are just as strong as anything else on the bike.

My opinion, of course, but then again, I do not go all wishy wahsy in the presence of Chrome Moly. I no longer buy into the hype of it being better that high tensile. Both, depending on many other factors, can offer wonderful ride quality.