If Cervelo, check to see if a shop will place Di2 on a P2 for a similar price or, more likely, simply swap out the aero bar for something better like the Profile Design bar that comes on the P2. Otherwise, the Felt offers a larger fit range including independent tilt adjustment of the pads and extensions. All their new bikes come with the V3 clamps, so that's not an issue.
Brakes on the Felt are better, and the front Vision aero brake is what would make it a "faster" bike out of the box. I don't understand the issue with the rear brake. For 2018 it's the 105 direct mount and easy to set up. Works great. Last year, some of the IA's had Shimano direct mount, some had the FSA. I didn't like the FSA as much. I'm still not a fan of the head tube compartment for the Di2 junction box, but it's a little better this year with the 3-port junction box instead of the 5-port from last year. Though, now that I think about it, the 48 doesn't have that compartment, so better to put the junction box in, or under, the Calpac anyway.
Jim Manton /
ERO Sports