Glad to see that you're still on the cold water case.
There's a ton of gear on the market these days & unfortunately, there's an even greater amount of bad advice on cold water paddling, cold water safety etc. smeared all over the web So what's a fun-loving yakker supposed to do when the water gets cold?
Always dress for the water temperature - no exceptions.
OK, fine. But how do you KNOW that you're wearing enough thermal protection & that it's working properly? Only one way to find that out, doggies:
Swim-test your gear:
2) Get in the water & splash around
3) Hold your nose & dunk your head.
4) How long you stay in the water is up to you - it's your gear that you're testing, and it's your life that's on the line if you wind up in cold water.
Good, effective, cold water safety advice should be practical, useful, real-world tested, and easy to follow. No matter how high or low-tech your gear happens to be or how much of it you're wearing, swim-testing gives you immediate, real-world feedback on whether your gear is great and up to speed or whether it doesn't have a prayer of keeping you warm in the water.
There's nothing wrong with less expensive gear, and also nothing guaranteed about gear that costs a small fortune. The bottom line is the same for both: Does it work? Will it keep you warm in the water for however long you need it to.
There's also nothing wrong with wearing a 2mm farmer john and paddling jacket combo - unless you try to use them in conditions -challenging or otherwise - for which they weren't designed and in which they are virtually useless - like, say, 50F water.
Swim-Test Bonus: Far better to find out that you forgot to properly close the "relief zipper" on your drysuit when you're still at the put-in rather than half-way across Big Duck Lake.
National Center for Cold Water Safety