Crane,
I've got no experiance with the Vortex, but I do have a 4.5 x 22.5 x 50 Clearidge Ultra XP5.
I can't think of a bad thing to say about the XP5, it's been a great bang for the buck in a mid priced hunting scope. Low light ability is all you could ask for in normal hunting hours. Glass is bright and clear all the way to the edges. Best of all its been very repeatable since I got it.
Chris