If you have an iPhone then I guess you wouldn't know about custom ROMs huhI see.
Never had a problem with GPS lock. Takes about 0.5seconds to get a 30meter radius lock, another second to get an accurate lock.
One of those would be a nice substitute for a HTPC for someone who has a server to store all of their media.
I remember seeing a while back that some company was putting out a similar system based on the Samsung Exynos 4210 from the Galaxy S2 which would be excellent for HD video playback.
Have you tried any 1080p video on yours yet? It seems to have a Mali 400 gpu which is a promising sign although I'm not sure if the video playback hardware is the same as what Samsung uses or not.