Here's some pictures of the 800mm mirror lens. I went hiking yesterday but I didn't bring the mirror lens. Instead I chose to bring a wide-angle and 50mm prime lens. I don't regret it, because the 800mm is quite impractical and heavy. It will be fun to do a dedicated 'zoom trip' in the future, though.
Both shots were handmade on a fairly bright day. The blurriness is usually user error, either because I was shaking the lens too much or because the focus was slightly off.
Side note: I actually miss the 17-85mm lens! I've been using the 18-200mm that I bought last winter, and I am leaving the 70-300mm home because of it. Bringing both seems superfluous but I can't bring myself to leave the 18-200mm home as the range is so useful. I guess I'm not the target group for the 18-200mm after all. I don't mind carrying extra lenses if it means I have more range or more quality (although there are limits, of course).