Yes. You have to pay full price except for on the 91 express lanes. It is free to drive on the 91 except eastbound between 4-6 pm when it's half off ($10+ some days for ~10 miles). There are no toll booths on the 91 so you must have a transponder and there is a minimum fee (I think it's $7 per month).
I avoid the 91 if at all possible and if going to OC I just take the 210 to the 57, milage is about the same and the 210 has a diamond lane all the way:thumbup: