I don't have one, but try reading this:
http://www.digitalhome.ca/forum/showthread.php?t=157621
My neighbor works for Shaw and he told me the 3510 is the first device they've programmed in house. The team working on it is small and is having a hard time resolving the issues it has. I'd wait until they get it working properly.
No, mpeg4 won't give you a better picture in my experience. It just uses better compression so they can offer more channels with the same bandwidth.