Good point! (Cog Psych shows that we don't really multi-task.) I've always been partial to beds and couches for reading ... and especially in the very early mornings ...
Anecdote about how time of day affects reading: Michael Silverblatt, host of KCRW's Bookworm and one of the country's best readers, says that during the day he reads at a relatively slow pace, say 50 pages per hour; but he will often wake up in the middle of the night and read an entire book over a few hours. I believe he referred to it as "nightbrain."
So, I'm not the only one. (Some of my best reading occurs in bed. I've sometimes felt a little weird about that, but as I've grown older, hey, if it works...)