Saw a company selling both gen 2 and 3 mags. What's the differance?

I know there were numerous reports of the earlier Gen CPD mags with all sorts of problems.
In my 2 AR builds(7.62X39) I have been using 8 of the 30rd Gen3 CPD 7.62X39  and have over 2000 rounds through them with flawless success so I can highly suggest the Gen3 CPD.

Edit; some good info in the last 3 post in this thread.

http://www.ar15.com/forums/t_3_17/684043_C_Products_mags_still_suck_.html&page=2

I've only seen their 30 round as Gen III, where the 28 round is Gen II. Sound like they updated the 30 rounder, not the 28 rounder (which is CPD only, not a left over C-products product).

I believe the main difference is the mag body geometry, and possibly spring. Having to have the straight upper portion of the mag for the AR platform doesn't lend itself to feed reliability with the x39mm round. Now with the constant curvature AK mags - never a problem.