I played for about 30 hours. When a massive amount of people get together on a tank convoy it's a lot of fun, but if there's no teamwork going on then it's slow paced and pretty boring tbh. But yeah, get 50-100 tanks into a flag capping frenzy and it's fkn awesome.
Don't like f2p, I'd rather spend 60$ on a game and buy it's dlc package if I like it enough. Instead of pay outright for weapons / gadgets.
Cert system is a huge grind, it's worth doing some research before you unlock something with your hard earned certs.