My last round of system upgrades (htpc and desktop) two years ago were driven by lowering power use... I retired a homebrew freenas box using an FX-8350, and was surprised at the change in the power bill... my htpc at the time was a similar cpu, and my desktop, I don't recall what it had at that point. In the end went with a couple i3-5010u's for htpc and spare, and an i7-4790 for my desktop (usually idle)... man did that make a huge dent in my electric bill.

Planning on a new NAS sometime this year, so hopefully will see something with enough oomph to do on the fly transcoding from h.265 to whatever my devices need. I've been recoding most of my media to h.265 for space savings, but wouldn't mind being able to direct-stream it to more things. Still think it would be cool to do a media server that targets chromecast devices.