still no digital in huh? It will never be as good as a D-8 or M-1 just having a little mini line in like that.
The D50 has digital in. Perhaps that's a more exact comparison.
My TCD-D3, which made some great recordings, required an external box for digital I/O, that I bought and hardly used.
Now that you can transfer your recorded files digitally to a computer via USB and memory card, digital I/O seems redundant, unless you're using a preamp with digital out.
For most situations, I like to take advantage of the handy small size of a unit like the M10, and keep the set-up to a minimum, i.e., no external preamp.