Has anyone here played that mod. Is it as good as it's said to be? I'm thinking to buy ARMA 2 for that mod because I have read so many good things about it but decided to ask here about it.

A small discussion took part here, though the search function does make it difficult to find, even if you do search for Day Z :(

I actually searched for just that. But no hits :( so thank you.

No worries, I recalled this thread because I couldn't watch the video at first, so I had bookmarked it. Also for search, it's much better to do a google search for "site:www.gog.com day z", though it was still on the second page or so.
The mod does look good, though it probably needs a party to enjoy it.