I got Pace weights but rely almost entirely on wrist weights now when I'm in-between on dumbbells. Since I started STS (I'm on M3 now) I've had ridiculously fast strength gains and have found the wrist weights (which I'd forgotten I had) much easier and faster to work with. I can't tell you how fed up I got pinching myself with those magnets. I think they're great when you first start lifting, especially when doing shoulders, where you can't really make big changes in weight. But as you progress and are able to lift heavier loads there's nothing like quickly slapping on a weighted bracelet fastened with velcro.
If you think you really need the micro weights and are on a program where you're progressing as fast as STS helps you to do, maybe invest in a small set of 4 magnetic weights and two sets of wrist weights. I have a big set of Pace Weights I'll likely never get much use out of now.