Well, I know this is probably a bootleg, but curiosity killed me. I bought it recently and here's my observation:
0. Sonically speaking, the 1975 Lincoln Center tape sounds so-so. I guess the tape speed is slightly too fast -- the voice pitch of the announcer sounds too high for me, but since I don't have the absolute pitch, don't believe me too much. The 1972 Village Vanguard tape must be an audience recording, so don't expect hi-fi sound. But I think it's acceptable, anyway.
1. Monk plays surprisingly well - much more energetic and inspired than the late 60s. He comps steadily behind Jeffery(which became kinda rare when he was with Rouse in the late 60s), and takes good solos by himself. Not ground-breaking, but still very good.
2. Monk Jr. plays surprisingly well, too - not flashy, but quite swingy and seems to inspire his dad(especially on the 1972 tape).
3. Paul Jeffery is smoking - I didn't know he was such a good player. Much more aggressive and inpsired than Rouse in the late 60s with Monk.
4. The biggest surprise for me is the presence of Dave Holland on the 1972 tape -- his walking bass line really swings. Holland might have been the best bass player Monk could ever get.
So, I should say this is not essential but an important recording, and it's worth releasing it under more appropriate circumstance (e.g. from Thelonious Records, possibly?)