I haven't found that there's much overhead at all. And there are a LOT of benefits... for instance, you can use a much leaner framework on the services side, si

I haven't found that there's much overhead at all. And there are a LOT of benefits... for instance, you can use a much leaner framework on the services side, since all you really "need" is routing. The services can (should?) run on separate boxes, so you can divvy up labor vertically. You can also version the API so that when you want to make changes, you don't have to upgrade your web app all at once.