Whitney in May is totally where it's at. I climbed it on a Saturday with a group of 3 in one day and maybe 10-15 other folks made it to the top. The lack of crowds was fantastic and it was a load of fun. Be prepared for snow and ice and it's good to have crampons and an ice axe for going up (and glissading down) the chute. We left at 4am, summited at 11:30 and got back at 5pm and it was great but did make very good time. If you're somewhat less experienced, of recommend leaving an hour earlier but it's really not too bad of a hike. During be summer months, I think it's akin to San Gorgonio just shifted up a few thousand feet (which does make a big difference) and during the winter, it's a perfect place to work on beginner mountaineering skills. Overall, a fantastic mountain and the tallest in the lower 48!!!