I want to describe what I think is the best 3D printing platform. I have been using a heated platform covered by a mirror for some time. I have used Kapton tape to cover the mirror glass. The adhesion of ABS is pretty good, even for large prints using this surface. Pre-cleaning with acetone makes it much better. The problems include the fact that one print requires new Kapton, but more importantly, it is very difficult to pry loose a part at the end of a print. What I am showing above is two separate, smooth aluminum plates, each 4″ x 8″ covered by Kapton tape. Due to the heat capacity of these metal plates, heat up and cool down time is significantly longer, but the distinct advantage of this system is that I can pull the plates in different directions (one up, one down) after a print has completed, and it always pops off easily. I can even reuse the Kapton since it remains undamaged in the process. I have used the above Kapton for about 5 or 6 prints so far. I still clean with Acetone each time, and my prints are not curling at all at the edges.
I purchased four of these plates on eBay for about $20 with shipping. I rounded the corners myself. The Kapton at the edge is to insulate the electrical connections for the platform heater. I find this surface to be far superior to anything else I have tried so far, and I have tried a lot of things!