I kind of wish Finn had killed himself to destroy the cannon thing - it would nicely mirror Dr Sattler's sacrifice from the beginning, and would nicely wrap up his story. What's left for him to do? Poe is the best of the new trio, Rey has got her Force stuff going on, but what is there for Finn? He ostensibly killed Phasma, which would have been a good ending for him, which they could wrap up with him destroying the cannon...
The little touches were nice, like the kid they freed using the Force to grab his mop, and BB8 using the coins the gamblers were feeding into him as a weapon.