no idea. downtown seems flat to me.
roof height of Zion is 278 feet. roof height of 12th and Idaho is supposed to be 290 feet (on the west side), though lower on the east side with the slanting design of the parapet, so east might be lower than 278. either way, they're comparable in height without the spire.
i read that if the Ovation gets built, the roof height will top out at 277 feet.
a 400 footer would be nice right about now.