As much as I love Disney, I just don't feel the need to stay on property unless the deal is too good to pass up (like when they offer free dining as part of the package). But at Universal, the convenience of staying within walking distance of City Walk and both Universal parks, combined with the automatic Universal Express Pass granted to hotel guests, makes staying on property the ONLY way to go!
I do agree, it is better in the long run to stay on site hotels at Disney or Universal
Oh, and you can send stuff back to your room or charge to your room at Disney. I am guessing Universal is the same.
Universal still offers room delivery at their three on site resorts.
The Extra Magic Hours, just like the Fast Pass, are awesome if you know how to work with them.