Help me pick an HTPC replacement

Late last year, I built up a home theater PC to replace one that had died. It’s got a very pretty case designed to fit in with audio equipment (protip: if you’ve got young kids or large dogs, don’t hook up the power button to the motherboard. Use the reset switch instead). I put a Blu Ray drive, about 6 TB of storage, and a massive amount of RAM in it. It’s a hoss of a box, and I’m not going to be getting rid of it.

The new house we bought has a great media room. It’s already wired for sound and has surround speakers in the ceiling. The HTPC would look great on the built-in media rack.

Unfortunately, the media room is a converted attic space. It’s not connected to the central HVAC in any way. Instead, it’s got a 13 year old PTHP that only has “on” and “not on” as options. They’re kinda spendy to run, and spendy to replace with newer computer controlled models. What that means is that this room will only be climate-controlled when we’re using it, which probably tops out at 2 hours a day.

Having an always-on server in that kind of situation is bad. I imagine that the room will get to probably 110F in the summer, before you add the waste heat that electronics produce.  I need some sort of set-top box that can do the following:

• 7.1 audio out, via either optical or over HDMI
• Handle a variety of video media in 1080p over DLNA or SMB, or run PLEX or XBMC natively.
• Not get killed by frequent power cycling

That last one is there because I’m probably going to put all my stuff on a switched outlet and power that guy off when we’re not using it.

We have a Logitech Revue we’re using in the bedroom now. It’s okay, but it’s discontinued and underpowered.

The Roku 3 looks like it meets all my criteria (PLEX has a Roku Channel or whatever it’s called)

The VIZIO Co-Star looks like it has promise, too only does 5.1 sound, so it’s out. I can’t find anything definitive about the Sony NSZ-GS7. We won’t be getting cable at the new place, so most of Google TV’s features are wasted.

A co-worker just got this and based on his experience, it’s probably not going to meet my needs.

I haven’t considered any Blu-ray players with network features. Should I?

What other boxes should I consider?