Looks interesting. I wonder if you can get 1-offs anywhere (I've not
looks yet). On the other hand, the 26LS3x's and the MAX232 are easy to
obtain (even though they take up more board area).
Just looked at DigiKey--you can get them, but I've seen cheaper MPUs! You
could also sample them from Analog.com
if your day job qualifies you.
As far as board space, if one were using DIPs, it'd be a hard call. The AD
IC is a 24 pin PDIP (also comes in SOIC).