Thanks. So it's like Canon's EF and EF-S and Nikon's Fx and Dx lenses. FA can be used on "full frame" whereas DA is more for APS-C. Apart from built, what about IQ on current range of DSLRs, like the K5, which is in my scope right now.
IQ wise the DA limiteds are excellent too, all of them. But they are overall a bit slower than the FA limiteds. I kinda miss the DA15, DA35macro and DA21. These are what the FA limiteds can't replace.
If I were you, I'd get the K5, plus DA15, DA21, DA35 macro and DA70. This would be a very good and compact combo.