First off, what the devs accomplished here is amazing. They aren't a triple A studio, but rather a bunch of talented people in the Half Life community. That in of itself deserves alot of praise.

The game looks beautiful and is very well detailed. It does a very good job at portraying the atmosphere of the original game and upping it with the Source engine.

Pretty stable compared to the mod, I only had one instance of stuttering though I think that was on my end, rather than the games end. There is a bit in Surface Tension where I got a big frame drop, in the pipe room with the marines and all the zombies.

My only problems with the game are all personal little nitpicks and nothing fundamentally bad or game-breaking. My "major issue" (which is, again, only a personal nitpick) is the HECU's voice. I was in the minority that liked their voice in the mod, my only problem was the delivery of the scripted dialogue, I liked the radio filter and how their combat dialogue was all from the original game ("Squad, we got Freeman!" "Recon team in position, all quiet.") with some new lines ("I'm tired of playing these games, Freeman, come out!" "I'm gonna get medieval on your ass!"). Now they just sound like Generic Marine Man, with none of the memorable quotes or the cool radio filter. And with their redesign back in the mod making their uniform and equipment more realistic, on top of their new voice, they don't feel like the HECU anymore. They just feel like Generic Military Men.

Overall, despite my own petty nitpicks, I would still highly recommend Black Mesa. I look forward with much anticipation to the release of Xen.