I used the 1.9mm a while ago because the 2.1mm out of stock. It's slower than the 2.1mm , but more controllable on a backhand short game. Backhand lift underpin it's harder than 2.1mm.
That's because you are cpen player, always use wrist. Try use more your body weight to make stroke will save your wrist. But that's depending on your body physics status. I change from cpen to shakehand because that.
Why not a vis for beginners? I don't get why some ppl say it's too fast or something, you can't play with it doesn't means others can't. As op said he bought it after a year, not beginner anymore tho.
Why not joola training ball? The you wanna try, some of them in the 100 pack are good, but some of them not that good. I bought more than 500 of those a few years back for community center.