I'm still a little fuzzy about the plus r and minus r and r versus rw stuff.
Without getting into details:
Do not make a DVD backup that you wish to keep on a DVD RW disc. You're wasting money by doing this. It's rewriteable but if you never plan on rewriting why waste the cash on it?
I'd recommend DVD+R over DVD-R. I think that's more of a personal decision but I'd never buy DVD minus blanks.
Are you saying the commercial dvd's are dual layer right off th shelf or out of Blockbuster or Netflix? I didn't know that.
Not all discs you buy or rent will be dual layer. It all depends on how long the movie is and what they added to the disc. I've bought some recent movies that w/o any extras had to be on a DL disc because of the length of the movie. Other movies I've gotten are fine if I back them up and just remove the couple billion previews and other stupid non-related stuff then they fit on a single layer DVD [without compression] even though the original was a dual layer. It all depends on the movie and what they decide to add.
Humourously enough I ran across 2 movies released in 2006 that I purchased. Unheard of titles that never were in theaters but interesting enough. Anyway, they were both single layer with
no CSS and they were locked to regions 1, 2, 3, 4, 5, 6, and 8. At first I wondered if AnyDVD was working right when I read the status window.