Yes, I do use this feature and think that it is a good practice for all developers to comment their api's. Once you've done this for a few apis, and as long as you stay on top of it, it's really not too hard to maintain.
Option 1: SandCastle
I tried using this, but I found that there were far too many installers that I had to run and install and learn to configure. In the end, I ended up with a chm file, but really I wanted something a little lighter weight.
The upside is that the end product looks very professional. It didn't work for my situation though.
Option 2: NDoc
Last time I checked, this project was not being maintained and only worked with version 1.1 of .NET.
Option 3: XSLT
Someone on CodeProject has written a xslt file for this
http://www.codeproject.com/KB/XML/XMLDocStylesheet.aspx
I've tried it, and here's how it works.
Build your project and drop in the xslt file into the same directory as the outputted xml file. When you double click your xml file, a formatted webpage will displayed instead of the xml document.
For me, this was the best option.