The like button wasn't very useful in my opinion. The review gives better resolution.
The "tried" button is feature to try to bring in new users who may want to keep track of the beers they've had without spending the time to review each one. Personally, there are hundreds of beers I've had in the last few years that I never reviewed and can't remember well enough to do so. This way I can at least keep track of them.
Soon there will be a new stat on your Dashboard with the beers you've tried, and top lists and other stats.
By default, if you
Review a beer, it has to count as a beer you've tried. So that's done automatically for you and I've already taken care of everything in the database to capture previous ones. I'll also put a symbol next to the beer name in the brewery list if you haven't reviewed it. Again, reviewing it would mean you've tried it, so no need to put both symbols next to the beer.