One thing you need to remember - error checking is better on the + standard. On top of that, you can change the book type on the + type which you cannot do on the - type. So you can change the book type to say DVD-ROM instead of DVD+R which enhances its compatibility with older players or for other purposes which I will not mention here.
DVD-R however has better 'native' compatibility with older players, but this is offset with +R's ability to change book type making +R the superior format in more ways than one. Error checking alone should make you only want the +R version.
-S
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