there's actually so much misinformation in this, and the language the dude uses does suggest he either didn't do his research or he's just not so confident in what he is saying- pretty weird. but we are the guys that were actually there so it's easy for us to be incredibly critical of stuff like this, whereas it's completely meaningless really to 99.9% of it's viewers :D.
He could've mentioned weapon economy, the ability to purchase improved weapons with cash gained from kills. I thought b5.2 was generally hailed as the best version of the game. Wasn't 1.6 just the last version where they left the progress before making source and go?
as far as the best version debate goes, i think 1.3 and 1.5 get most of the love. 1.6 is the steam version, which itself has been updated many, many times.