The Matthew Macfadyen ("Tom") centric reviews, of course

Variety: 

Matthew Macfadyen, a sleazy standout

and

Each family member follows his lead in their own deranged way, particularly Macfadyen, who brings into each scene an aura of menace and the stench of impostor’s flop sweat.

Collider gives it 4 stars

NY Times (possible spoiler!)