Foursquare was my favorite app ever, until they split it up into 4sq and swarm. then it became totally useless to me, and all of my friends slowly stopped using it. :/
4sq's venue ratings is hit or miss. I've definitely found some good places to eat at (that I would've otherwise not found), but I've also eaten at a ton of places that are highly rated but nothing special. For the latter, perhaps they are good relative to the immediate area, but not really that good.
Big fan of their SMS bot Marsbot as well if you haven't tried it yet. For some reason it's very low key and they don't promote it at all, but it's a pretty sweet product.
