Ahh as my first post I fell I shall weight my opinion in on this topic. I have ridden very few Vekomas first off. The main two that I ride multiple times a year are Everest and Rock 'n' Roller. I love both of those and have never experienced any overly bone jerking moments as I have on others. The statement that Disney had their hand on it I will agree with.
Everest due to its unique nature and the mountain that it i contained within would point toward more Disney designed input. The layout is fairly intricate and the way it is laid within the mountain is too uniformed for Vekoma to have provided a design and Disney go around it. I think the track layout was more Disney and contracted the building itself out to Vekoma with their fine tuning.
Rock'n on the other hand, I think Disney told them what they wanted and Disney oversaw the designing to ensure it's quality.
These again are my naked eye observations and no facts backing them up at all