I'm extremely happy with my 40" LCD Bravia/XBR set connected to my 622. As others have alluded, the HD pictures from cable and/or OTA will generally be sharper vs. those from E* due to the resolution/bitrate reductions through the satellite. This is the same more/less from E* or D*, "fondly" known as "HD-lite". But you should still have a very watchable picture in any case.
Three things that others have not mentioned in this thread: You might want to try both the component and HDMI connections from the receiver to the TV and choose whichever looks the best to you. Most have reported a difference, but it varies as to which they prefer. Component is often "warmer" and more color-rich whereas HDMI is sharper, but YMMV. And do make sure you were installed with HD connections! There are many reports in here of subscribers being connected with the S-video connections since generally the ViP receivers don't come with either type of HD cables in the box. (That's something that either the installer or sub. needed to supply themselves, and the installer is sometimes even unknowlegeable that there is a difference!) Also - you should try the many adjustments in the Sony to find what looks best for you. For example, mine has a "color palette" that I have yet to experiment with. But your brother apparently has other issues. Finally, since you also have a Sony TV that apparently works well for you, you could take it to your brother's place for a comparison. That would quickly tell you whether it's the TV or the satellite system that's making the difference!
Welcome, BTW...!