I told myself data collections weren't even on my list of stuff I was looking for...But they were so cheap... :(
I'm going to need to sell a few books when I get back, some I just never look at for lack of interesting information that isn't duplicated somewhere else. (Looking at you, Rapport Deluxe.)
The Dengeki Data collections were eventually translated as the 'technical manuals' for the US market.
The Data collections are usually pretty good at having good info, with the exception of the Macross one...That one is just a compact version of Perfect Memory.
It'll be up for sale soon somewhere...