Hi Chris,
sorry for that late answer, but the team had some vacation and some other things to do within the last weeks ;)
You're right with your problem. We've also noticed that CPU utilization isn't that optimal when transcoding videos. Seems like some defaults in our underlying encoder (ffmpeg) changed for webm video encoding.
We'll try to adjust our settings and make them some kind of configurable. Even if video transcoding (especially in 720p and 1080p) is always a hard task for a CPU, utilization should be at a maximum.
I hope we can work it out and get out a new beta containing these changes within the next days. I'll inform you, when we're done, so hopefully you could do some beta-testings on your machine.
Thanks
Thomas