Those roller things look interesting! I've never seen them nor do I know anybody who uses them. Straight line? Fairly straight, but in quite a few places there's all sorts of tire hazards that require a quick duck to the left or the right. I'd think that would be a better indicator of skill---able to quickly manuever like that without going down. Pacelines are pretty uncommon around here so I don't have a chance to really test that skill.