For a few months now I've been doing the instant watch first on my laptop PC, and now on my PS3. For me both have had really good picture quality, most of it has been pretty close to what I get on DVDs. I watched the first couple episodes of Red Dwarf, the first on the laptop and the second on my PS3, and both were about equal to what I get when I watch a show from that era on my baisic cable analog TV. It was the first time I'd ever seen the shown, and I thought it was really funny (I watched it with my mom and she enjoyed it to). The only problem I've run into is that my internet connection tends to randomly cut out, so it has taken me a couple (or 3 for Chronicles of Narnia: Prince Caspian) to finish some of the stuff.
As for Farscape, I've watched the first couple season 2 eps (I bought season 1 on ITunes before I got Netflix) and I must admit I forgot just how great the show really was.