I finished all three last year and got my polka dot gear, too. I signed up this year for Mulholland, but a knee problem is keeping me out, drat! The same knee issue slows me down in the best of times, and when I have finished Mulholland, I've done it in the nick of time.
So instead of riding Mulholland this year I will be doing roving SAG. If you break down, watch for a white Kia Sorento coming to your rescue.
And when doing a ride like Mulholland, keep your nutrition up during the ride. Last year I bonked about a mile from the finish. I searched my pockets and found 5 energy gels and 2 crackers. Inhaled it all, and did the last mile.