I have an upright and a Henry but I find them not great for the stairs and also carpet edges where all the dust settles !
Anything you can recommend handheld or whatever but with powerful suction - have light coloured carpet so all our trafficking about really shows.
Plus if it can do the above and be small to store away it would be like having lunch with George Clooney -fab 
. .... Mind you in RL he is probably boring !