Now that I'm voted out I can share a secret
Graphene has been so rock-solid that I was able to scale back my infrastructure to running a single t2.micro (plus a physical machine at home and another t2 ready to spin up in seconds).
Even on this low-end setup CPU utilization is close to zero, RAM is safely at around 60% and no latency issues.
During the two-months I've only had 33 missed blocks, all before the vesting-pay-bug fix. I now only scale up the machines during build.
Now, some witnesses are maintaining several four-core, 8GB machines, and you might think that it's somehow more secure, stable or scalable but the thing is, they have to dump their earned BTS to pay the bill. Meanwhile, I've never sold any BTS and am still able to easily scale up if/when blockchain usage picks up.
Graphene has exceeded expectations in terms of stability and footprint so much, that we ended up overpaying the witnesses. We can easily have twice as many witnesses or slash witness pay by half. And if the Blockchain starts demanding more resources we can always reevaluate.