We did the all inclusive and found it well worth it. One day had mimosas with breakfast, but we usually had pre and post-dinner cocktails. I really liked not having to think about it, not caring if my drink wasn't great, etc.
Beyond the drinks, I also liked the idea that wifi was included (I needed to check in back home a few times) as well as tips. We still tipped extra (in cash) because service was that great, but I liked having the basic tip amount included.
Bottom line, once we deducted what we'd pay for WiFi as well as tips, we calculated that we'd break even around 5 drinks/day. That was close enough for us to purchase it ahead of time. The convenience was well worth it (and we never had an issue getting drinks).