I do agree some reviews over sold it, this game is not close too be a 100/100 game. I've spent some 3,000 hours in TF2, so its actually 0 no content expect the maps. The maps are also amazing, I'm not sure how but it feels so natural, I could easily guess how too get some where, what other routes I could possible take, where heals should be even on the first play on a new map.
But mostly this game is a competitive PVP game. It doesn't really need a huge amount of content, LoL and DoTA2 have 1 map and 1 mode and thats it. Its all about mastering the heroes, and either taking it serious once the ranked is out, or relaxing in the casual game. So far what I've seen from the casual games are great. I like that I can get on for 30mins and just have fun then log out. No need to rank up too unlock something, no need to grind out guns, its just good fun. I feel the price depends on how much you will enjoy that experience, and enjoy PvP only games. My time on Destiny for example I think is 80% PvP and it used too be 90% before I started running more raids during TTK.
For me its worth the price, but yeah its not close too a perfect game for everyone. Also I think reviewers where just happy that they didn't suck at an FPS game for once. Also currently most big games are full off bugs too the point where its not playable at times (Division for example). I've not seen a single bug or even a hiccup which would have effected reviews.