re: Wanting to hit Bryce, Zion, Grand Canyon, etc in one trip in April.

I've actually been to all 3 in one day, but I was leaving from Flagstaff, spent most of the day driving, and spent the following day in Zion doing Angel's Landing and some of the Narrows. Spent very little time at the Grand Canyon but stopped for a bit on the north rim because the route to Bryce Canyon led me past there. Hiked the amphitheater at Bryce and was able to drive through Zion during sunset to stay in Springdale. I hope your trip is less rushed than mine was.

To actually answer your question, Vegas is closer.