Aye Up,
I've just had a look at the SF Stealth jacket and it appears to be made out of the same fabric as the Trojan.
I was issued with a full set of the Trojan and used it operationally many, many times.
It was probably one of the most abused pieces of kit that I have ever owned - used way beyond what it was probably designed for including prolonged immersion in ditch-water etc and it always kept me dry..
The construction was excellent and it was only the continuous abuse that the jacket suffered which eventually forced me to retire it. I've still got the trousers (patched up to high heavens) as a back-up set. If the Stealth is of the same quality it should be good.
My only reservation about buying one now is that I prefer the dark olive (as per Fjallraven gear) to the light olive of Kmoor SF but if that isn't an issue go for it but remember that it is synthetic so take care re open heat sources.