I had the Sony SAT-A50 and I have to say that I liked the menu and Guide system a lot.

However I just got the Toshiba DST-3000 and I think their menu and Guide system is even better than SOnys. On all their guides, it stays on the channel you are watching while you search through the guide. It also has 4 different TRANSPARENCY settings so you can see right through the guide. I have to say its the best menu system I have seen on a DSS system.