Great Romero feel! My biggest complaint is that it feels a bit too close to Abandoned Mines structurally - the ambience is different, but the whole 'lift down, platform + cliff on the left, looparound climb to the right' is quite similar.
As for other details:
+ The secrets were very well placed, especially the plasma gun, which echoes the original Map17 - they rewarded a careful eye, Romero's main signature. I might add a switch texture though - 'press stone wall to lower lift' was very much a Petersenism.
+ The geometry of the AV ambush really sold it as a new fight - close, but with a clear passage out
- I think the intro from a pistol start is a bit rough for a Map17, and a bit uneven - nearly all my deaths were at the start due mostly to bad luck with chaingunners. The good news is that after that, it was even, with a few close encounters and enough health afterwards
- I do think the key guards could use some work. The RK ambush is just well telegraphed imps after the hell the yellow switch brought, and the YK courtyard with the revenants and pain elemental forces you back without anything to pursue. A quick suggestion would be to put the revenants on the ground and the sarges and/or hell knight in the cage, but even then I'd think hard about it.