I've been running infxludb 0.9 + heka 0.9.x + grafana 2.x stack in a production environment for over a month. Mostly successful, although I find the grafana tooling for building queries to be a bit weak. I think there are improvements coming soon to address this, though.
Overall, influx performance seems to be pretty good although we aren't ingesting enough data to say anything really concrete. We also make use of continuous queries to aggregate our time series, which of course makes large-interval queries more efficient.