I'm currently trying a 2mm thick piece of acrylic sheet as a build platform. I like the idea that it is lighter than the glass, so in theory it should have less inertia when the platform starts and stops. And ABS seems to stick quite well, but on one occasion I tried wiping the sheet with acetone. Unfortunately this enabled the ABS to stick pretty much permanently. Hey no warp though!
Time will tell how the ABS stands up