Hi,
I don't have an exact answer to your question, but I have used zanaflex myself once and I have friends who swear by it. I had a reaction to it where it made my throat feel like it was closing up, so I don't take it now.
My friends, however, swear by it. My very best friend uses it nightly because it knocks her out completely. It is so strong, in fact, that she can time her need to go to bed exactly by when she takes her zanaflex. Otherwise, she finds herself running into walls and getting bruises from striking tables and things with her wobbly legs. Her husband (also CP, but a serious abuser of medications) takes them by the handfull. I do not recommend or approve of any abuse of medication of any kind. He has come very close to death from his abuse of this medication. Apparently it causes euphoria in such large doses and he does not seem to care about he long term issues associated with the abuse.
I would highly recommend speaking to your Dr about reconsideration on this medication. Anything that can make you that dizzy will most certainly affect your mental ability and that is of great concern to me if you are driving. I know most meds we take can (and many do) affect driving ability, but I am very concerned for anything that is still causing these symptoms after taking it for more than a few days. My friend (not the addict) has been taking it for YEARS and still has the immediate need to sleep after taking it.
Good luck in finding the correct med. Soma was a wonderful muscle relaxer for me, but sadly my PM let the DEA scare him into chaning all of his patients at one time to a different muscle relaxer. First I went to one that made me very sick (can't remember name right now) and then on to Robaxin (which I don't find useful at all).
All my best!