(MK2) PCB heatbeds vs silicone pads

I hear mixed opinions about these:
https://www.youtube.com/watch?v=eure74A9HNc
http://www.soliforum.com/post/72807/#p72807

http://ts4.mm.bing.net/th?id=HN.6080....1&H=106&W=160
VS
http://ts3.mm.bing.net/th?id=HN.6080....1&H=106&W=160

I just need my whole bed area to be hot enough for ABS to stick to it, even close to the edges.
Some say PCB beds provides even heat distribution and parts don't lift/warp on the edges and say silicone pads do not provide even heating and have high fail ratio,
Then others saying the complete opposite that PCB beds have 10-15C temperature variation from middle to edges and silicone pads below an aluminum bed are better as the aluminum allows the temperature to become more even unlike say glass on top of PCB.

So who's right?
Or just share your stories. What's the biggest you've printed with your heater of choice with no warping / lifting.