My main complaint about these sites is that they are all, to various degrees, very user-unfriendly. They try to include so much information that it makes the UX very unsatisfying and confusing. One particular issue the prominent display ads that infest most of these sites. All too often, they are designed so that they look like actual content instead of ads. So you click on it and are sent off site thinking that you are merely entering another section of the original site.
My first impression is that it is incredibly easy and clear to use. There are very few ads (although I'm not sure if that is intentional or due to a lack of advertisers). The navigation is simple and easy.
But what I really like about it is the Disease and Conditions section. Once you find your particular condition, the article that pops up is easy to read, clear, and loaded with practical information. If there were a "Dummy's guid to Diseases and Conditions", this is how it would be displayed.
So, I highly recommend visiting this site. It's relief from the crowded world of medical information.