The smock 'concept' is a good one. Wear a t-shirt or warmer shirt underneath. Easy to unzip and throw on a sweater (or 'jumper' if you're from the UK) when you stop. Much better than the button up cdn combat shirt in that regard. Pockets big enough for the stuff you need to put in them (although the popper studs sometimes gave out, and could be noisy). Tough and hard wearing. Baggy, long enough to just about kneel on. Not tailored, so you could vent in hot weather, or put thicker layers on underneath in the cold. The Cdn Abn smock material wasn't a great 'venter'. You could also wear the INIBA flak jacket underneath quite easily and make yourself look like a heavyweight boxer. It was cotton and fire proof - found that out the hard way a few times. I doubt the cdn cbt shirt/ Abn smock could take a molotov cocktail without going up in smoke. Weighed a ton when soaking wet though and the Cdn shirts dries faster. Have to keep Gary Gore-tex handy. The rest of the army in the UK were issued a copy of the Para Smock in the 80's. The first runs had crappy material though and it wore out/ pockets fell off and had a generally poor fit. I saw a whole arm come off of one guy's 'pseudo-smock' once. They must have fixed that by now. Luckily we were able to stick with our Para smocks. Cdn combats always seemed better fitting with higher quality finish than some of the stuff they came up with in the UK back then.
The SAS type windproofs were good too, excellent for tabbing above the treeline in all kinds of crappy weather. The arctic windproof was excellent in cold weather, especially north Norway. Similar material, but longer cut with a wire rimmed hood. Monster pockets with proper flaps and buttons to keep things in. Kept the wind out so you could ski at temps down to minus 30 with a wool/cotton blend Norgie shirt and HH thermal underwear quite comfortably. I remember several occasions when I had to chip the sheet ice off the front of my windproof after a long ski march to unzip my windproof and didn't even notice the cold inside. Fast drying too. However, few windproofs survived the blackthorn hedges in South Armagh longer than a couple of weeks, or the barbed wire fences of Salisbury Plain for that matter,and FIBUA of course. Smocks were preferable in these environments.
Ahhh... the good old days (yeah, right)