FWIW, Bil Paul did the route planning for Adventure Cycling.

My daughter and I rode the southern portion of it last year. I found it to be extremely beautiful and extremely difficult. You are either climbing a long steep grade or descending one at pretty much any spot on the portion of the route that I have seen. There are almost no flat spots for the whole section we rode. Combine that with 100F + temps and it makes for a difficult ride.

On the other hand, the scenery is breathtaking. Sequoia was pretty amazing and Yosemite was worth taking several days off to see properly. I usually do not take rest days but found it worth doing so there.

One of the hardest things about the route is that you are likely to be stuck weather wise, because once the passes are open the desert is likely to be extremely hot. I am not sure what the best way to handle that would be. We started in San Diego in the beginning of June just after Tioga Pass opened and had a lot of 100F + heat in the desert and even at that time the only facilities open in Yosemite were in the Valley. We had a high of 115F and a low of 32F just a couple days apart so be prepared for a wide range of weather.

I have speculated that starting in the North as late as you can get over Tioga Pass before the snow flies might yield a cooler ride in the Desert. That is only speculation on my part and it would be hard to pick the time well.

I have a trip journal at http://www.crazyguyonabike.com/doc/MountainMan if you are interested. You can also find other journals for the route on the same web site.