[tomsem]

Clearly some people have issues (they complain because unlike K1, K2/DX doesn't allow use of SD cards). Their concept seems to be that Kindle should contain their entire, mostly unread library of free ebooks, but it's not designed for that. And if you put image laden PDFs or especially audiobooks on there, storage will get chewed up pretty fast.

But I find having many items on my Kindle becomes 'clutter' long before storage is an issue. Also, when Kindle needs to reindex (e.g. typically when there's a firmware update or some other issue to clear up), that can take a number of hours if storage is close to full, and you kinda have to let it finish before you can use it for reading again. So just as with a computer disk drive, you want to leave some margin of free storage to keep things happy.

In terms of reading material, I just keep it on there only as long as it takes me to read it, along with a few PDF documents that I use for reference purposes. I send samples to Kindle4Mac so they don't add to the clutter on my Kindle. I find that only very occasionally have I pulled something out of Archived Items to read again.