Daniel, early May, even in a low-snow year, is pretty early to hike to those elevations in the Sierra. You are likely to encounter high stream flows from the rapid melting of what snow there is, and you will be hiking over considerable snow once you get up to the 12,000' elevations of Shepherd Pass.
Shepherd pass sees less than 1% of the traffic compared to Whitney, so I'd assume you will be breaking trail. But the snow will be well consolidated, so should not pose too much additional work. Looking at your Whitney report, I doubt you will encounter anything worse than you did on that trip.
