The biggest advantage would be the preset level buttons. I have a hand crank and it's a pain to get the desk to the level I think I want, only to sit down, get comfortable and realize I need to go up a few inches. So then I have to get up again and there is just a lot of fastidiousness sometimes.

My (IKEA) desk at work has a hand crank, too, but it's easily within reach when I'm sat down.

I still don't use it much, though, since I don't feel particularly productive when trying to do my work while standing.

Keep in mind that this is an accessibility issue - many people cannot use a standard desk comfortably or at all. Height-adjustable desks are a convenience for all users, but they're a necessity for wheelchair users or people with musculoskeletal disorders.