I own or have owned many ereading devices but still use the Kindle the most. Why? Whispernet and the web kit. That allows me to download any book directly from Calibre without sideloading. I also have close to a dozen feeds that are automatically generated and sent to my Kindle.
I can do the same on the Pocketbook IQ and my Droid as long as I use Dropbox but then I have to use a file manager to move it into the Kindle folder if the file is mobi. If the file is ePub it is automatically opened in Aldiko. The process is not as dead simple as on the Kindle and the Kindle has the distinct advantage of the Pearl screen.
I'm definitely not a sheep, blindly following Amazon's lead.
I only see commercials during the news or football games (thanks to my media server) and have never seen a Kindle ad but the ubiquitous iPad ad is on many times during football.
Still waiting on the Honeycomb Android tablet.