overall in my opinion dvd readers are roughly the same (get some other people’s opinion’s though before doing anything )… should be no drastic differences in reading abilities if the disc are in decent shape (i.e. minimal to no scratches) and the burn quality is decent… cause i suppose that if your dvd’s burning quality is questionable that could potentially cause big difference in reading time.
as far as the ‘dual layer’ question… unless you NEED DVD+R DL discs (i.e. for something like XBox360 etc) overall i would just ‘compress and use 4.7GB discs’ since it’s alot cheaper and quality aint that much of a difference… cause your looking at about 30cents a disc (or less) for Verbatim DVD+R vs roughly $1.50 a disc for dual layer.
all in all though… you can get a pretty good all around burner/reader right this moment on newegg.com for $19.99 out the door … http://www.newegg.com/Product/Product.aspx?Item=N82E16827106228
also a word of advice… burn your 4.7GB DVD discs @ 8x (no more than 12x) if you want to keep quality of the burns high especially if you got a slightly older burner… but generally speaking 8x burning speed on anything 8x certified or higher is a safe bet overall.
also, buy either Verbatim DVD+R (16x certified) discs or TY (Taiyo Yuden) DVD+R (8x certified) discs if you want quality discs that will last a while… most people in these forums will agree with that comment
also nowadays the best software for backing up DVD Movies is either … DVDFab or Slysoft’s ANYDVD. (ANYDVD + CloneDVD is a good combo)