I read somewhere that it could be due to door seals shrinking with age, but honestly I recently replaced a torn passenger side door seal and did not notice a significant difference in wind noise between the left and right sides of the car.

I haven't done the window seals, but the door seal wasn't too bad. It's a press fit, so you just pull the old one out and press the new one in. You'll have to unbolt the door check strap at the frame, and you may want to have some light talc or baby powder (or similar) to lubricate the new seal going into the channel.