I recently switched my Heroku app DNS setting from using A record at the apex to using CNAME record at www subdomain, because of the scenario outlined in this blog post: http://neilmiddleton.com/the-dangers-of-a-records-and-heroku/
Supposedly, this is "the right way" to do this. However, since I made the change, I have noticed my response time spiked from about 360ms on average to over 1,000ms.
Pingdom chart: http://stuff.stevepaulo.com/FV74
Is this a natural side effect of using CNAME records? Is there anything I can do to speed this up? Is the danger of using A records a whitchhunt, in which case, I should go back to hard-coded IP Addresses in A records?