Tbh, if you haven't got someone that completely understands this game from the start it feels crap as that's how i felt on the beta.However, after frustratingly working out how to squad up it was so much fun. You don't have to buy any microtransactions as its a bit like CoC so if you want a boost in xp then do it but it won't win you the fight.
It needs polishing, especially how you join up but there is a really enjoyable game there waiting for a grind.
My only hope is that there is enough variety in the game to play it. I might use the PS trophy system to help give me some more tangible goals as the fight is 24/7 and never stops.