It seems that you found a way that is convinient to you when it comes to your clothing gear. Apart from that, i take the fact you said "it's not who made it but what it does that's important".
Of i will carry standard clothing with me but let's take an example: Say you are in vietnam and while super humid and hot you have the summer layer on. But 10 min later is starts to rain, a lot. So you stop and put your waterproof layer on top.
Whereas if you had a single layer jacket, my experience says that you will either get too hot in a place like this, or you want be protected from heavy rain as no textile (not even Klim is 100% waterproof). But that's in extreme rain conditions i guess.
On the flip side, the waterproof layer (e.g Reissa lining) is trully waterproof in the heaviest rain. I tested it my self in extreme rain for about two hours of riding (at 30km cause i couldn't go faster, in fact i could barely see in front of me).
I was surprised to see that my t-shirt was absolutely dry when i stopped.
So, going back to the Siima Sibirsky i believe that this jacket can truly do the job in multiple climates. Of course there is only one way to find out.