Those of you considering installing a glass plate, should also consider using a sheet of PEI. On the advice of a friend, I installed it, and it's amazing how well it works. I printed a PETG part last night that took the entire length of the bed and about 3 inches wide, and after about 2 minutes of cooling, it just popped off. Preparation is nothing more than a quick wipe with paper towel and alcohol. I've used it with PLA and PETG with never a stuck part.
http://www.amazon.com/gp/product/B00...ilpage_o09_s00
One sheet is enough to do the bed two times.
Cheers,
Joe