Then here we are with only 1 layer change,
To robert, for high speed less vias always wins, Unless you get very creative there will always be some form of impedence disturbance,
Coupling reduces the amount of noise that can get into a differential system, however a large bump in impedance can make far more noise,
In general on any design where high speed is required, I group very tightly around the fast components, to make sure that even if i screw with the impedance, that i try and stay under the magical 1/4 wavelength where possible, (impedance still matters, but the disturbances are attenuated faster as they have to traverse less transmission line before hitting a termination resistance)