Once--me, too. I have a 740 and a 740b. The 740b is noticeably easier to read in flight on a sunny day. (The number of "nits" a manufacturer claims is almost irrelevant, I've found. My iPhone and iPad both have fewer nits than the 740b but are considerably easier to read, partly because their displays are essentially non-reflective.)
On the other hand, my 740 downloads updates considerably faster than the b model--getting all of the charts usually takes about half a day for the 740 and a day and a half for the 740b. With the same internet connections, the iPhone and the iPad usually do it in 1 to 3 hours. So I'm looking forward to AP's new tablet (even if it is Android, heh).