The first thing I noticed is that after downloading the latest (very large) version from the website and installing, it immediately connected to the site to download a new(thankfully small) update. Why not just have the latest version on the site?
Anyway, thats a small point. This is different from the other searching programs I have tried because it offers a filtering process AFTER you get the search results - you choose "catch" words which move matching auctions to the top of the list and "trash" words which remove matching auctions from the list all together. This allows you to build quite sophisticated searches. The search results display is probably the best I have seen (except for timeBLASTER), showing gallery-size pictures along with the auction title, price, bids and time left.
All in all its a search tool thats well worth trying and a more pleasant experience than eBay's own search!