I'd say it's likely that ISO 6400 is probably as good, or better (in terms of look & feel of the noise) as ISO 1600 on those bodies.
I spent about 10 years doing medium format & then digital studio and location strobe work. Highest quality, big prints, never never never above ISO 100.
Time to explore some new terrain I guess. Amazing tools we have today!
I did a lot of blurry, grainy, challenging images when I was a Photograpy undergraduate, and in B&W. When I went to almost all color in 1998, I kept going to more refined, pure, beautiful color, smooth tonalities, big prints on my 7600 & 9600.
Time to mix the two I guess.
Dang, I ordered the 5D3 2nd day from adorama and paid $51 to get it here Friday. A Canon 9500 II printer, with free ground, ordered and shipped the same day is also getting here Friday. You think they might have said hey, free will get there .... (Free said 7-10 days.)
Oh well ... Back to our regularly scheduled L glass fest!
Thanks for helping. And nice web site too, nice images. Have fun!