Those are the plastic problems I was afraid of. And if I didn't break it to start, I was scared that the heatbed would warp with the heat. And lastly, that the whole frame would shift over time, especially when moved from room to room. So the steel route was better for me; completely eliminates these problems, and I expect it to be a good frame for many years:
http://3dprintboard.com/showthread.p...eatec-in-Spain