Better quality picture from SKY+?

Thinking for a while now of upgrading to SKY+ from the standard box. Main reason is to record the odd show, series link etc. Now the sales girl in SKY has said that another advantage of upgrading is that you receive better picture quality because the box is "more modern".
Is she talking through her hat?

Simple answer, yes.

Talking through her hat that is!! The picture quality is the same as normal Sky box.

...but I believe Sky+ gives 5.1 surround sound, while the older sky boxes are simply stereo.

It's possible, newer box would use newer components, may have better shielding, etc. Probably not much of a difference though.
Leo