Specially, it allows customer can filter products via manufacturer, product min price, product max price and product types (Virtuemart 1.x) and custom fields (Virtuemart 2.x).
New version of VM products Ajax search can search products of Virutemart 1.1.x and Virtuemart 2.0
I was very happy to see that not only was it very easy to install, it was very customizable and allowed great flexibility...two things that you sometimes dont see with Joomla extensions.
Having used Joomla since 1.0, I've seen a lot of new tools come and go, but I would definitely say this is one of the better ones out there.
As far as support goes, my questions (albeit few) were always answered very quickly and in a very personal manner. I always felt like I was dealing with someone who cared about the customer, and that goes a long way to getting my loyalty.
Two thumbs up!!