I have just upgraded to the new 360, I have two boxes.
The problem is the second box has no hard drive, something that I was not made aware of.
This means you cant hold programs or rewind them if you missed the start.
Both of these are a huge step backwards compared with the V6
It also means there is often a lag whilst the main box wakes up
I would go back to the V6 if it was an option.