We hired an RV in SF in 2013 and drove it down PCH to LA, then inland via Bakersfield to Yosemite and dropped back in SF.
Setting off from SF for the first time was truly terrifying, the RV was the size of a removal lorry! However soon got used to it and within an hour it was all OK.
We didn't find PCH an issue at all and drove that quite easily in our huge RV.
Cities are a problem, but that only affected us in LA. We stayed in Malibu which was not far out and drove into LA once to have a look around and find the Hollywood Sign. RV in LA was not fun and we just spent ages trying to find the sign (which we did eventually) then headed out of the city.
We planned and booked our stops in advance and stayed in some absolutely spectacular sites on Monteray Bay, Big Sur, Pismo Beach, Ventura, Malibu, Fresno & the highlight - Yosemite. You need to be very organised and book the sites as soon as you can so you have the best choice and location. Particularly Yosemite which sells out literally a few minutes after going on sale in peak season. RV is not an easy thing to move around so if you are stuck in an out of the way site you are restricted.
We found driving and parking easy enough but we had planned it all well in advance. The Pro's were the cost and freedom of the road. The cons were slow progress so driving took longer, and having such a large vehicle to park up if we wanted to stop anywhere.
I would say it is definitely worth doing at least once and staying on the great sites in the National Parks. But if you want to explore cities and be more flexible car/suv and hotels/motels will be better. Whatever you do take care what RV sites you choose as some are part tourer/part permanent sites which seem a bit iffy - easy to avoid those by planning in advance.
We booked through
ideamerge/united-sta...-van-hire.html. They were recommended to us and the RV hire all went very smoothly.