Eric Roe wrote: What's new in the 4th edition? Worth getting if you have the 3rd?
300+ new routes, added pictures and topo for dozens of previous published routes, better quality paper. Errors fixed from 3rd. If you frequent leavenworth it's "worth" it. (Stupid puns)
If you go there occasionally, the 3rd edition is fine. One thing the 3rd edition has the 4th doesn't is an alpine section. Viktor refers readers to Blake Herrington's guide.