[noggin]

Thanks, and I think you did a good job of doing that. I think the i3 vs Celeron is slightly more "future proof" although that might not matter at all with the trend for XBMC towards lighter/cheaper and less capable boxes like FireTV and Raspberry Pi where users don't care about full codec support and true 1080p playback capability.

in terms of video decoding, there's no much (any?) difference between the HD4000 and HD4400, outside of 4K. The real issue is neither can (HW) decode x.265, so once XBMC starts supporting that, CPU power for software decoding will become relevant.

I'm in a minority - but I went for the i5 NUC for my main HTPC rather than a Celeron or i3 because I needed 4:2:2 H264 multithreaded software decoding of 1080/50i - and I wasn't convinced the i3 would be up to it.

When it comes to H265 HEVC 4K - the 2160/59.94p and 2160/50p stuff currently being broadcast OTA in the UK pushes my over clocked (4GHz) i7-2600K to the limits (it can do a crop but can't quite do a real-time scale to 1080p) using an OpenHEVC fork of ffplay (which is more efficient on Intel CPUs than standard ffmpeg AIUI) Obviously 2160/23.976p stuff will take less CPU - but at the moment I don't have access to those sources.