buffered vs. unbuffered outputs?

The unbuffered will sound better if you have short ICs to the amp and a high input impedance amp - 100kohm would be ideal, otherwise, you might prefer the buffered output since you will need buffering to drive the ICs and amp properly. In a well matched system, as I described above, unbuffered will sound better than buffered (to most people).

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.