Thanks a lot for your input.
I have a lot of space and don't mind cutting a bunch of changes ahead. But i should really try out what you said about the traction...maybe it has to do with the snake not being 100% in touch with the surface? (just speculating there)
i kinda hate newspaper and paper looks not so good in plastic cages. Again it's only my preference. If i had tubs i would surely go for paper. I'm feeling you on aspen, but i really wanna move away from substrates (either wood or coco) for the above mentioned reasons.