My opinion, there is only so much talk you can have about one device and the discussion of other devices is very limited, for good reason. Most people who find that site are Kindle users.
You cannot discuss things like DRM removal, rooting, and the like because it violates KB rules. So some of the hot topics here are pretty much off the table there.
I think that sites like this do well because there are so many different devices represented which makes it easier to generate conversation and help.