If you want a nice ML with low GC latency, how about Rust?
(Did you look at tuning the GC? As a Scala guy I know a some people write off the JVM because the default GC settings are optimised for throughput rather than latency (whereas Go does the opposite), when often their requirements are comfortably within what the JVM can do when suitably configured. That said I've heard the CLR is less tuneable)
Rust is too complicated for me to learn and be productive with in a reasonably short period of time, and the CLR is not good at keeping GC pauses down. :-(
(Did you look at tuning the GC? As a Scala guy I know a some people write off the JVM because the default GC settings are optimised for throughput rather than latency (whereas Go does the opposite), when often their requirements are comfortably within what the JVM can do when suitably configured. That said I've heard the CLR is less tuneable)