I still have as my only ereader, a prs 505 which I love. I'm aware, however, that it's probably coming to the end of its natural life. Already the battery's totally flat and I'm using it plugged in via the charger while waiting for a lazy techie friend to change the battery.
Half-heartedly looking at other readers incase the battery change kills my 505, I'm disappointed that Sony only have the T1 to offer. The main thing I don't like about this model is the refresh-to-black-every-turn. Kindle seem to have overcome this, doing a full refresh every six page turns.
Much as I'd prefer a Sony, there have been so many issues with the only one they currently offer, even taking into account the new firmware update, I think I'd purchase the Kindle Touch.
Kindle's eco-system isn't appealling, but they seem to understand what the market wants in its ereaders.
The 505 is just what an ereader should be: readable. Since then Sony have gone crazy.