So, it's a good start...
I don't own an e-reader, seen them on the tube, not sure they've got enough words per page for me but essentially I'm agnostic.
The kobo blurb on openness attracted me, I would have found it helpful if you'd checked on how open it was (its seemingly major differentiating feature) rather than commented on a groupware feature that doesn't appeal to you and will only be effective when its market share grows.
While I'm not a member of a reading club, if (for instance) such a club consisted of peripatetic work colleagues then the possibilities of remote participation through margin notes and/or other stuff seems like a feature that might work. If the feature needs to be discussed at all, then it seems like WHS doesn't deserve the faint denigration I infer.
FWIW, from a reverse perspective, soon I might be meeting some international people at a nerdy IRL event, whom I've sort of grown to know via the texting discussion facility of the web based equivalent.