Have you had any bad performance surprises ? To me, knowing that beam has poor pure computation performance made me look away. I don't want to build a magnificient immutable actor architecture only to end up writing parts of my system in C.
My interest in ports/NIFs (and Rust as a specific implementation platform thereof) is less for performance and more for doing things that aren't really easy in a VM-driven architecture, like dealing with low-level device access or interfacing with native libraries/APIs.
Basically: I'd try it first before dismissing it for supposedly-poor performance. There's a reason why Erlang is considered to be a "soft real-time" language, after all :)
OTP is also not tied to a certain cloud provider; a couple of Raspberry Pi boards duct-taped to a WRT54G can use the same codebase, deployment practices, and application structure as a bunch of EC2 instances in a VPC with an Elastic IP. This is usually not true of "cloud" tools (things like Docker and Cloud Foundry are helpful here, granted, but a lot of the tooling around load balancing and such is often provider-specific).