From my experiance with my a03, all the media I have thrown at it has worked great.The one I have a problem with is media from cd recordable . com. The dvds I got from them are not made very well, their thick, and if they get the slightest bend the disk comes apart like an oreo cookie. The ones I am talking about are the ones that have the weird textured face side, sort of a cheap looking prismatic effect. I bought 50 disk bundle from them and 10 were bad. So their quality sucked and the company did nothing. Merit is really great, and a few of the hong kong companies are real cheap. The best advise I can give is when you get your dvd recorder, experiment with various media from various manufacturers. When you find one that works stick with it. If you plan on making dvds to play in a settop box , find a media that will work with that. Settop boxes are more picky than the recorders. Heres a trick for testing, get a porn dvd and use your drive to copy it to a dvdr (no ripping required, they dont have copy protection)(just copy and paste) if it works then your player likes the disk and your set to go, if it doesn't then its the disk because all you did was a one to one copy.
also dvd recorders hate the fat32 filing system, try to go for a ntfs. and with a dvd recorder their is no such thing as to much memory.
You can work with a fat32 system but every so often your dvd when played back on a settop box will be a little jerky and sometimes freeze.