It felt different after the update for some people, including me.
Though the cm/360 with accel 0 was exactly the same, accel seemed a little bit slower to me, so I increased the value of cl_MouseAccelPower until I got the same feeling as before.
Probably will work for you as well.
Yeah I have no idea why but I had to change my sensitivity too. I was at sensitivity 3 and had a cm/360 of maybe 27 or 28 I think. After the standalone update, the same sens would give me something like 150 cm/360 (maybe a little exaggerated). I had to bump it a lot (and added a little accel since I was at it; I had none before) to get something usable. My m_cpi is still at 400 like it was before. I don't know what could have changed.
Assume the wmo is 425 dpi and recalculate the sens that way. The deviation shouldn't be *that* big but I wouldn't be surprised if it was big enough to throw you off.