I just got to the end of Black Mesa and I have to say, that it was awesome. The chapter order was changed for the better. One disappointment: no Xen 🙁
I WANT MORE! The conversion is fantastic.
And another thing. Seeing that Gordon Freeman is a 27 year old man made me feel old.
If you have not played it yet, head over to http://release.blackmesasource.com/