FOX looks good on Bell too - the fact that it is natively 720p helps a lot, especially when it comes to lack of artifact on fast moving images. The biggest problem with Bell's quality is when they cut the bitrate and downsample to 720p the 1080i US feeds, while FOX's 720p feed has lower bitrate to start with and does not suffer much, if at all. Also, the "lack of artifacts" can often be the result of very aggressive noise removal, which can easily create the illusion of "better looking picture" at the expense of effective resolution.
Nothing for or against Bell or DirectV in general, especially without being able myself to see DirecTv's HD, just pointing out that the setting of this comparison - in a pub, obviously from distance and without seeing the same materlial on the two providers side by side - no conclusions can and should be drawn.