I have a handful of plates from JC, among other brands. I would happily buy from JC, but will admit I don't tend to buy any standard shape plates from JC any more, simply because I can find better prices elsewhere. I don't pay for paint - I have to repaint every session anyway, and I tend not to be bothered by a little surface scale which other folks might cite as "lower quality plates." I've shot thousands upon thousands of rounds on "scaly plates" and haven't ever seen them give up any faster than more expensive, more refined versions. Anything AR500-550 will last as long as you don't bang them with something too fast.
JC, Champion, Shooting7, Bullseye Metals, AR500 Target Solutions, Caldwell, Birchwood Casey... I'm sure I'm forgetting some here, but if you get AR500 or 550, they're going to last.