I don't consider it a waste of time, I think a lot of people that don't even know about Recorded Amiga games watch stuff like this on Youtube. And personally I don't think quality is all that important in longplays, you're not really watching them to admire the graphics or anything. As long as the quality is OK, I don't mind personally when watching longplays.
I have read that tutorial now however and I recorded Colorado using that technique so it's much better quality than the Wrath one.
I'm currently looking through my harddrive trying to find these longplays as some of them are pretty old and I saved them in pretty random places and I've even forgotten the names I used.
I'll upload them either today or tomorrow provided I still have them all. I just found the Dragons Lair 3 one and that one is one of the oldest ones so I think I have them all still