I do love RSS feeds - having all the web sites I check regularly in one place - and only having to look when I KNOW there is something new is a wonderful thing! I use Bloglines and I love how it works. I have a little Sub With Bloglines favorite, and all I have to do is click on it when I find a site to which I want to subscribe. Google didn't seem as simple to me, but it wasn't hard either, and it may just be getting used to a new interface. I probably won't switch though, have some concerns about privacy on Google.
RSS feeds can be great for me in my job - I subscribe to a number of cataloging and Tech Services blogs, and get great ideas, interesting news, and all kinds of information that helps me keep up with my profession. I would think the same could be true for anyone, in any job. I'm sure there are just as many blogs for reference or childrens librarians as there are for catalogers.
RSS feeds are a great time-saver - they would get my vote for one of the best things to come out of the Internet.