What is holding up First Byte

[JamesAtPulsate]

I think to dismiss Cloudfront's because of their DNS approach is a bit premature. Each CDN has pluses and minuses. One thing I will say about it is when you make a change in CF it propagates very fast and you also benefit from their DNS infrastructure is which is likely to be stronger than other (non CDN) offerings available to you. The fixed cost per month is a predictable one and the device\connection aware image delivery is a big benefit if you have mobile users looking to buy from your ecommerce site

Swings and roundabouts. Both CF and MaxCDN are great products.

But when testing and server tuning, yes you will want to put your CDN in development mode (if available) so that you are testing directly against your server.