I've started up the OpenELEC option on a freshly installed NOOBS image, and while the interface is telling me it's running at 1920 x 1080p, it isn't. It's running considerably lower than that, and looks quite low quality and blurry. If I select 1280 x 720p it looks much crisper, but of course isn't actually using the full resolution of my display. 1080p works just fine in Raspbian, so I know the hardware is capable. If I go back and select 1920 x 1080p in the XBMC preferences, it goes back to being quite blurry again.
Any hints on where I can make an adjustment to a config file or something to force it to be nice?