I bought 2 used 505's in the last 3.5 years. As long as the batteries continue to last, my wife and I are perfectly satisfied with them.
We just read fiction, so we don't even need wifi really.
That being said, I thought I accidently killed one of the readers last week and even though I was like "Oh crap!", inside I was secretly glad. Cause I now had a "legitimate" reason to look for another reader
But it started charging again this evening and is now right as rain. So no new reader in the next 2 months anyway...