Titanfall 1: Your speed accelerated during wallruns, starting at your run speed (~20kph) and capping at 2.0x run speed (~40kph). This took chaining two or more wallruns together, but this max speed could then be maintained indefinitely, as long as you continued chaining together wallruns and bunnyhops
Titanfall 2: Acceleration is gone, instead hitting a wallrun seems to instantly bump you up to 1.5x run speed (~30kph). When you boost yourself out of the wallrun, you immediately go to 2.0x run speed (~40kph) while airborn. This drops back down to 1.5x if you hit another wallrun, or 1.0x if you land on the ground (bunnyhops can keep you in the air at 2.0x)
This results in the strange clunky feeling we are getting. As you try to chain wallruns together, you are jerking between 30kph and 40kph, being faster in the air and slower on the wall. Whereas in the original title, you would maintain a consistent, smooth 40kph (and getting there was a smooth-feeling acceleration)
tldr;
T1 ground = up to 20 kph
T1 wallrun = up to 40 kph
T1 airborn = up to 40 kph
T2 ground = always 20 kph
T2 wallrun = always 30 kph
T2 airborn = always 40 kph
FOV reduced, creating illusion of slowness
(airborn being when jumping out of a wallrun)