50/50. I love both for different reasons, and often use them together. For anything that requires tweaking (like lighting with flash), I'll get everything worked out using the DSLR, and then pull out the 6x7 or 4x5. A DSLR is a killer light meter.
The DSLR is also great for social/party shots and concert photography. Plus, the film version of your DSLR usually costs less than a battery for your digital. I picked up a featherweight EOS Rebel Ti recently for $20. It's nice to shoot full-frame without having to pay for (or lug around) a 5D. 🙂 Loaded with neg film, the Rebel Ti is also a one-shot HDR camera by digital standards. I went to Vegas recently and didn't even bother taking a digital camera -- only neg film can handle the signs without blowing out.
I love my Mamiya 7, but I love the luscious 6x7 negatives and transparencies even more. There's no portable digital camera that can come close. It's a monster.
For portraits and other more carefully-composed shots, you can't beat 4x5. I think of my Super Graphic as a $300, 100 megapixel camera. Or in other words, Super Graphic: US$3.00/MP. Rebel XTi: US$68.00/MP. Leica M8: US$465.53/MP...
Ha 🙂