I don't think that the 800 will give you anything you cant do with the 600 from a technological standpoint. That is to say, they both learn IR commands, they're both programmable, and they both utilize IR-RF in a similar fashion.
What you pay more for is the computer programmability, individually assignable IR flashers, and more remote macros, programming memory, and devices.
If you don't
NEED that, you'll be happy. If you're going to miss the computer programming, you can get an
IRClone-MX. This will give you easier access to discrete codes and allow you to back-up your remote. As well as making programming it easier.