My hands, like the rest of me, are getting old (or have already arrived at old) and are a bit on the weak and shaky side.
I can't really hold onto the bare Oasis very well with just one hand; even if I partly support it with my fingers under the bottom of it after a while my hand starts to shake or cramp.
Nevertheless it's just so attractive that I've been reading with it bare anyway. I just use my other hand or a pillow or armrest to add support. I use my other hand to turn the page anyway, via the touchscreen. The page turn button would really need to be right in the middle between the top and bottom button for me to easily use it.
I've always left the covers on my ereaders and held them mostly in my left hand (although I'm right-handed) with additional support and page-turning added from my other hand. I've noticed that if I do read on the Oasis with the cover on I automatically open it like a normal book, fold back the cover, and hold it in my left hand with the wide bezel sitting off uselessly to the right. So I'm obviously holding it wrong.
I think the Oasis is partly a package of odd solutions looking for problems but I do like it very much anyway.