I just removed heating elements from my printer. I'm using TESA masking tape over glass bed and it gives me more grip that I really need for printing PLA. I print very rarely in ABS (fumes and stuff, my fume extractor don't do good job and... ABS stinks, like.. smell is very unpleasant for me). You print faster without heated bed, if you print in PLA and PLA composites or PLA like materials, you just need some adhesive or something they can grip. With ABS... well it is working for me, but I would not recommend not having heater for ABS (and other ABS like/based materials), for reasons that many people pointed out already.