I just put the XL Pingo on over my L Shak.
The hem of my Shak was completely covered. If I raised my arms up over my head, the Shak hem peeked out, but when I put my arms back down the Pingo slid back over the top of the Shak. No Shak showing, and I didn't even have to adjust anything, it just did that by itself.
I don't expect this to be waterproof on a long very heavy rainy bike ride. But from what I've seen so far it is very very water resistant. I have every intention of wearing this on rainy bike rides, I think I'll be much more comfortable in this than in my GoreTex. (I sweat far too much even for GoreTex or Triple Point Ceramic or any other "breathable" membrane or coating. I am a sweat monster!)
Not sure what temp range folks could wear it in without overheating. Everyone is so different, I can only speak for myself. I'd be comfy wearing this walking or cruising on the bike with a t-shirt underneath up to around 60-65 degrees or so. With the Norgie and Switchback underneath I could be happy in the snow. (25-30 is about as cold as we get around here)
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson