Took the plunge and bought a DA40XS kit yesterday
For us K-7/K-5 users K-01 makes theoretical sense as a video/MF lens platform along with our main camera, my reasaon being 1)it's video capacity is good, 2) still image quality just as good, 3)works much better with MF lenses because of the focus peaking 4)shares battery with K-7/K-5, 5)lighter/smaller form factor.
Actual thoughts after fiddling with it all night:
1. Focus Peaking is great, my fast A and M lens feel so much more usable with it, so far I only use it on household items and love it, have to take it out to the real world to see how it perform in the field. Be interesting to see how I feel about the green button after some field use as I find it rather fiddly at this point.
2. AF performance under room light is slower to much slower than K-5 depending on lens, plain and simple fact, maybe in good day light it will be different, but AF performance is not the factor that attract me to K-01. In indoor artificial light condition AF for my telephoto lenses are so slow it's almost unusable.
3. Responsiveness was beaten hands down by K-5, but within expectation.
4. Tried with Metz48 AF1 flash and exposure seems consistent from the few test shots with different settings, build in flash can't be use as wireless flash trigger.
5. Feel much much better with small primes than with zooms, I intend to use F28 A50 M85 with it as a kit, and they all feel so nice together. Your DA21 40 70 will feel right at home too.
6. I think I will get a Crumpler Noose wrist strap for it instead of the provided neck strap.
7. I bought the boring black/silver version, but the yellow one looks really funky in person, according to the shop owner they shift quite a lot of K-01s, especially to Asian customers.
8. DA40XS is a nice little thing, so thin and light, I might not keep it though as I prefer metal lens, I want the full fat Limited version if I feel the need for this lens, but I don't cause I have FA43.
I will take it out today with various lenses to see how it perform in the field(Vivid Sydney tonight
)