My comparison between the Black Mesa 2015 Version and the 2017 December Update (recently been released). Hopefully I covered everything!
EDIT: Everyone is asking me on how to play the 2017 December Update. In order to play it this is what you'll have to do: Go on your Steam Library and right click on Black Mesa, Click Properties, Click on the BETA TAB, Select Public Beta and click OK, Finally give it time to install. It took me about 20 mins to install on my PC.
Also,
RIP Crossbow: 2012 - 2017
Want this game? The store page is available here: http://store.steampowered.com/app/362890/Black_Mesa/
Also, why don't you check out my steam account?
http://steamcommunity.com/profiles/76561198332604947/