Playback of SD video via streaming website Hulu.com didnt cause any problems, but when I switched to an HD video and went full screen on my monitor at 1680 x 1050, the Athlon X2 4850e really had to flex its muscle to keep up. CPU usage peaked as high as 82%, which means there isnt much headroom to spare for programs running in the background. The video itself wasn't lagging but had the movie been of a higher resolution (this was 1280 x 720), things would more than likely begin to slow down. The same video clip in a smaller windowed version peaked just shy of 70% CPU usage.
I also connected the X1200 to a 50 plasma television using the integrated HDMI port for use as a HTPC. There were absolutely no issues when using the HDMI connection. DVD playback using the systems 16X dual layer DVD writer was flawless. Surfing the web and playing games is really nice on such a large display, but you will certainly want a wireless keyboard and mouse (or long extension cables) if you plan to use this as a permanent HTPC.
Using my APC Back-UPS XS 1500, I connected the X1200 to monitor power consumption both at idle and under full load. According to the Back-UPS, the Aspire X1200 uses roughly 40 watts at idle and just south of 80 watts under full system load. For reference, my main system (Core 2 Duo E7200, 9800GT) consumes 130 watts at idle and a full 200 watts under full system load. We also recently reviewed an Intel Atom desktop system that would consume 44 watts at idle and about 53 watts under load. In this day and age where going green is all the rage, the X1200 certainly fits the bill in this category.