I don't really see advantage. Are they the jerseys with added weatherproofing?
No, very different. The fabric's completely different - it's windproof on the PTJacket. More of a softshell fabric, which is why I can't work out what the difference is between the PTJacket and the PTSS.
Not yet. Give it time though - still trying, unsuccessfully so far, to think of a reason why I need a PTSS as well as four PTJs. Suggestions welcome.