I have the NXT4 and a Palatino and an Alegro and they all sound good on the gig and in practice through the MarkBass 121P. I have also played them through the GK MB150 and a few of the Acoustic combos and a Phil Jones Briefcase, I dig the MarkBass myself and I get compliments on the warm sound.
Check out John Burgess on YouTube and search for others too, there are few EUB users with the 121P I've come across.
Low Down Sound cab club #1
Markbass Club Member #287
Fretless Club member #559