So far McLaren looks to have the most impressive car. There was lots of detail hidden on the McLaren, i.e. lots of bits that they will add for testing, plus the gains they have made, they sounded very confident about. I just cannot see this Ferrari becoming a pace setter - it will be better, but I think at best it will be on level terms with McLaren and RBR, but much more likely it will lag behind.
I know everyone will say it hasn't even hit the track yet and will be completely different in Barcelona, but these are just my initial thoughts and seem to be shared by the likes of Gary Anderson, Craig Scarborough, Mark Gillan, etc.