I generally shower shave... Mach-3 on the noggin and straight on the face.
It adds about 10 minutes to my shower, maybe a bit less... add the conditioner/aftershave (alum if needed), stropping the blade, etc... after the shower
While I always headshave in the shower, if I shave my face at the sink, then I bowl-lather and it's about 20 minutes total.
It is all these preshave and aftershave routines that slow people down. I have a goatee and use a straight and the blade is only touching my skin for about 10 seconds a pass!