Aren't there a lot of unanswered questions about this unit? Referring to this thread:
http://taperssection.com/index.php?topic=153273.0
Not really (as far as I'm concerned). The issue is people don't understand SPDIF vs. AES compatibility and expect all digital DACs to communicate with all digital recorders. That's not reality.
The issue of these threads is whether the older digital devices (such as a Mytek, mini-me, V3, or AD2K) sent out digital data in a specific format. AES data is different than SPDIF data. The Tascam DR100MKii specs state clearly that it is SPDIF compatible (nothing said about AES, but we've confirmed through testing that it is NOT AES compatible). The Sony D50 also isn't universally backwards compatible with everything that was sold before it was designed and released.
That said, most of the more expensive digital recorders are happy with either AES or SPDIF so the question about compatibility doesn't come up with those units. But the cheapest more expensive digital unit is a PMD-661 at $600 (if someone wants to pay $300 more simply because they can't figure out whether their digital device is SPDIF compatible, is that a problem for Tascam?)
What this means is that, for anyone considering buying the DR100MKii it becomes important to figure out if the signal you'll be receiving with it is AES or SPDIF. If it's SPDIF, you should be fine. If it's AES and you're expecting compatibility, you'll probably be disappointed (however, as documented, the DR100MKii does indeed lock on a 16/44.1 AES).
So, I don't think there are any unanswered questions really. The compatibility question on the DR100MKii has been flushed and is well known for the DR100MKii. However, that might not mean that it's clear what...say an AD2K might be sending out since it's an older device that may or may conform to the SPDIF standard that was finalized after these were designed.
Bottom line, know your device and the digital format standard it sends and match that up to the recorder you're buying.