Check
this one out.
From thier tests, DVD-r's are more compatable than DVD+r's with DVD players. (96% vs 87%). My interpretation is that if your in the worst 4%, you cant play either anyways, and if your in the better 87%, you can play both, so theres only a 9% chance that you can play a DVD-R on your set top and not a DVD+R. IMO, its pretty doubtful that you fall within this 9% with any devices you have. (See Edit below)
However, DVD+r seems to scale faster. (DVD+R 8x came out before DVD-R 8x. I also read somewere that DVD+R is better for multisession since the gaps between sessions are smaller. There may be a few other things too.
Prices are about the same.
I know theres alot of fuss about if + or - is better, but my suggestion is just to find whatevers on sale and snag it. Each as subtle pros and cons, but its not enough to justify paying any more money for.
I personally have a Dual 4x Liteon drive, have only used DVD+-Rs for data, and have never burned a DVD+R, so I'm definitly not the most qualified to say "doesn't matter". I've been using DVD-Rs since they were the same price the last time DVDs went on sale, and I just read the compatability article I linked above.
All I know is I'm going dual layer once they come out. You can quibble about + vs - now, but u cant argue with 9 gigs on a disc. If you can make it through the winter, I'd suggest you do the same.
---EDIT----
I made the assumption that the 4% that couldnt play DVD+R also couldnt play DVD-R. Apparently its not, so my %'s are off. Assuming thier all mutually exclusive, there can be up to 17% of players that wont play one but will play the other. Maybe a dual drive is something that would be good to invest in if you are going to use it in several players, or you have an old DVD player.
Ive read that XBox will only play DVD+R and PS2 will only play DVD-R.