Kneewalkers at WDW anyone with experience?

My DW broke her leg and ankle a couple of years ago and now can't walk the grocery store without big time pain and swelling.
Doctor has suggested a kneewalker for making long walks (like a wdw trip) tolerable.
Has anyone any experience at theparks with one of these? Other than AK the parks seem smooth and at least wheel chair friendly. I'm concerned about the buses.Wonder if they'll let me hold on to it or if it would need to be "secured".They're light enough and the handle folds down making it fairly compact.
Any help would be great ! We're 179 days out so she's got time to practice:thumbsup:

DD had a kneewalker for a few months last year after ankle surgery. It was wonderful and amazing, but there is no way she could have managed the mileage at Disney.

We rented her a wheelchair for the parks, and it was much needed, there just was too much walking for her.