Anyone here have any thoughts on AppEngine vs Heroku?<p>I use AppEngine for my experimental projects because I can get a simple data model and some handlers running in minutes and a (supposedly automatically scalable) useful backend up in less than a day, and at very low cost.  (Virtually free if I use an *.appspot.com domain).<p>You do get lockin issues but don&#x27;t you also get lockin from Heroku?  Is there big advantages to Heroku that make it worth it?