I have a floor standing hoop with quite thin 'feet' which slot under the couch; This means that I can get it quite close to me. I have to sit a little bit forward but with a cushion behind me, it doesn't hurt my back at all (although I am susceptible to back and neck trouble from an old whiplash injury);
Can't comment on a lap hoop I'm afraid because I've never tried one, but I love my floor hoop!!
K x