I'm in something like the same boat you're in. I am NOT a current Indigo user, but I'm very very jealous of what appears to be its rock solid reliability, not to mention local processing. I'm using SmartThings, and after nearly two years of use, I'm right on the fence of throwing up my hands and throwing out my zigbee stuff to convert to Indigo.
Before you more seriously consider SmartThings, you owe it to yourself to read this entire thread on the ST community forums.
https://community.smartthings.com/t/upd ... ance/42547
As for IFTTT, I was super enthused about how it has ST compatibility. But experience showed me IFTTT is SLOOOOOW and their support is almost entirely unresponsive.