I recently tried to get a used hybrid for a commuter, and found that going used wasn't worth the time and effort involved. Seemingly, no one can ever tell you the frame size in advance, and you end up trying out bikes that aren't going to fit, and are going to need substantial investments in terms of new parts, etc. Basically the same story as your old bike, but without the sentimental attachment and knowledge of where it's been!

(Of course, you've got until winter if you don't mind commuting on the road bike for now, so you might have better luck than I did - I got tired of the hunt quickly...)

I guess it depends what your needs and desires are, but if you've already got the fancy road bike, consider just getting an inexpensive new bike...

Good luck!