Just a quick final follow-up. Thanks again to you all!
I ended up buying the MOT 2408MK3 PCIe and it's been working great. I can get very low latency plus the IO is great.
I have it hooked up via TDIF. Bought an inexpensive TDIF cable with the unit, then purchased a more expensive TDIF cable. I can't really tell any difference, input or output.
Also, this setup is so much more stable than the FW card interface I used to use.
Yes! More life out of my DM-24s!
Cheers,
Wally