It takes some getting used to but after a while you wont look back. Saying that IE whilst browsing with FireFox is only a right click away "view page in IE" a great add on but best of all is "searchstatus" excellent for webmasters with PageRank view (if it ever comes back) Alexa bar, Meta Tags view, Archive.org view, show robots.txt, show whois, show indexed pages, show backwards links. I love this feature much better than IE IMO.
I would say no they don't, every person i have ever spoke to or helped setting their computers up or teaching the basics to surf the net haven't a clue what its for, how to get it, or what it does. And even when you explain it there not interested in it, but why should the average Joe Bloggs surfer be interested in it?
Maybe thats why they have pulled the plug as it is mostly used as a webmaster tool.