I've been running the last couple of tests on an ASUS Chromebox, and have had a good experience with consistent 45+ fps.
Version 40.0.2214.114 (64-bit)
Platform 6457.94.0 (Official Build) stable-channel panther
I'm loathe to "upgrade" my current version as we're aware that people on the latest few builds have been experiencing pretty consistent "He's dead, Jim" crashes after about 20 minutes ingame (regardless of hardware platform).
But definitely, if you want to share info etc, let me know what you want from me!