How does read.amazon.com compare to play.google.com for ebooks? While I have a Kindle this would lead me more towards Amazon, Google seems to give more full samples and the cloud reader is less laggy. The flip-side being that converting e-pub to mobi with send-to-kindle doesn't bring all the Kindle lock-in goodies.
Is it largely a matter of picking your DRM poison?
What are costs/difficulties of escaping from either Amazon or Google?