Rogers fully supports HDMI; in earlier years they did not.
Just a couple of months ago, I had a Rogers technician come to my place to check some of the issues I reported. He wanted me to unplug the HDMI cable from the box, and connect my TV through component video cables instead, to see if the problems will remain. His explanation was that Rogers DOES NOT officially support HDMI connection. Of course the problem had nothing to do with either HDMI, or component cables, but that's a different story.
With regards to HDMI cable replacing multiple video and audio cables, that is generally true, of course, but keep in mind that if you use only 1 HDMI cable between your box and the TV, you most likely will not have surround sound, the way it should be (coming from a Dolby Digital 5.1 receiver and distributed to your surround sound speakers). Something like a combination of 2 HDMI cables and an appropriate receiver, or 1 HDMI cable and 1 either optical, or coaxial digital audio cable, plus a receiver, might be a better solution, to get that desired home theatre effect.
IMHO, the difference in picture quality between HDMI and component video connection is only marginal. I'd still say that the HDMI connection gives a somewhat clearer (brighter) picture, but that is barely noticeable.