With the Slingbox 500, you should be able to attain a picture quality identical to that of your set-top box (up to 1080p!). Bear in mind, however, that this is limited by your internet speed and the screen you're streaming to (particularly when it comes to brightness).
Regarding those discounts, however, unfortunately not; one is offered by our 3rd party authorized retail partners, while the upgrade offer is from us (pay special mind to the fine print at the bottom of our upgrade page).
Hope this helps!
The Slingbox Answers Forum Moderation Team