I did have an idea to fix that warping issue.  And its this:
http://www.tapplastics.com/product/plas … sheets/516
They sell pieces up to a half inch thick and im sure some places sell inch thick pieces.  It may take a bit longer to heat but I feel like it wouldnt warp AT ALL with this!  Thoughts?

I don't know much about the thermal conductivity of lexan, but I think anything above 5mm would take forever to heat, if ever.

Andrew

Pros for Lexan;

Parts, ABS and PLA stick really well, really really well.
Take the Lexan off the head bed and bend it, parts pop off
Cools off quicker, doesn't burn hand like glass
90c ABS printing, bed heats up to 90c fast, (110c for glass, very slow for the last 10c)

Cons for Lexan;

Get's etched by the parts, the patterns start showing up in later prints, not a biggie
Parts stick really well, eventually found that removing the lexan and bending it to pop them off.
Many binder clips required to keep Lexan flat on heated bed, need to remember to drop Z before homing XY
Lexan eventually won't be flat, and thus print bed isn't level anymore, get new Lexan.

Glass lasts forever if you don't break it, but the Lexan isn't that expensive, and I can cut their default 8x10 sheet with a saw, glass I need them to cut.... ever seen a 16 year old try and cut glass at Lowes.... oh dear.

Andrew

First off it looks AWESOME.  Second,  I have never had a build platform that let things adhere this easily.
Heres what I have found so far!

Poly/Lexan
Pro's:
Amazing Adhesion with no form of glue, hairspray, and very little to no heat.
Looks Cool
Parts pop off w a little cold compressed air
Cons:
Bends up just a wee bit with heat but im testing how low I can go with the heat and still have it stick.  Even with it bending up I just use a couple binder clips and I have 0 issues.

And now for the Acrylic!
Oh wait I havent tested it yet.  Ill update when I get to it!