A600's and 1200 can be easily modified to give an svideo output...
One TV I have here, with a scart input, the quality actually appears to be worse than svideo... its a Grundig tv, and just doesn't seem to scale the signal as well...
RGB/scart to ypbpr appears to give a good picture, the best I've seen actually... but not all tvs will accept this signal, so its a bit hit and miss if you go that route...
Now, not from my own experience, but from others reviews (and youtube videos) rgb to hdmi will give a picture that's worse than svideo, and barely an improvement on composite.... well, lets say somewhere in the middle