Calibre is excellent, especially if you're trying to stay DRM-Free. Calibre has come a long way in a short time. And being cross-platform makes it all the better. It's available for PC, OSX, and Linux. I definitely recommend checking it out if you have a supported reader, which includes the PRS-500, PRS-700, Kindle, and more.
Also, thankfully it will manage your DRM'd files too. It can't do much more than move them around, but it at least can read their headers.
I can also attest that Calibre is a very useful program. I've used it to convert 800 texts to the mobi format my iRex iLiad prefers.
I've had varied results with the RSS feed feature, sometimes my subscription to Ars Technica, Wired and Engadget failed to download.
Calibre could also definitely do with a speed up.
The program can freeze on mass deletions and format conversions.
I'm running Calibre on an atom CPU netbook so that may account for the lack of speed I've encountered.
I'm interested in hearing other people's experience on more powerful machines.
I hate to be the nay-sayer but I don't like Calibre.
The interface is ugly and very amateurish.
There is no automatic sync.
And the format conversions come without previews. So it's a hit and miss kind of operation.
That said, there is nothing better.
Which is a problem.
Agreed. It is not too pretty. My biggest problem is how lock-upy (but not crashy) it is.