buffered vs. unbuffered outputs?

ELizabeth is right, listening is the way to go, but the amp
impedance is critical, but has little (nothing?) to do with
how loud it will play, the impedance mismatch effects the
frequency spectrum. Your amp has a very high input impedance
for an SS amp (100 kohm) so it should match very well with the
TLC's unbuffered outputs:) Which will sound better to you?
Only you can tell, but with this match up, the unbuffered
outputs should outperform the buffered as it does not seem you
need any buffering to match the impedances and using the
buffers just adds more electronics to muck up the signal -
necessary when you need it, but you shouldn't.

I had the TLC-1 and DNA 0.5 deluxe. To my ears, the passive (unbuffered) output was decisively superior. Like Pubul57 said, the input impedance of your amp can easily handle a passive. In fact, I believe Steve McCormack designed it that way.

All your replys were very helpful to me. I've started listening with "new Ears"
and I think you are all correct! Unbuffered sounds more realistic and un-embellished to my ears now that I've taken the trouble to compare really carefully. Thanks again everyone.
Ed