Played around with it in person today. I'm surprised by how small the 11" is. I prefer it as a tablet, but I can't see myself trying to balance that thing on my thighs as a laptop. On the other hand, I can't see myself using the 12" as an ebook reader in bed. Decisions, decisions.
how big are your thighs? 12.9 is fine in bed - maybe for regular books its too big in portrait, but landscape you can do two pages. Great for comics though.