hmm.. ok... i can´t really explain the technical pros & cons of DVD-R/RW -RAM +R/RW
I can only write down my personal opinion... maybe somebody isn´t my opionon ...just post yours ..
1. DVD-R/W
seems like -R (pioneer) will be the standard for DVDwriteOnce media.. Sony announced a DVD Writer which is able to write -R and + RW ....
-R is available for longer time than +R is (since CeBit?! not very old this standard) this is why the medias r cheaper ... there r also very cheap brand DVD-rs cause in Apple computers the Pioneer A03 is built in (superdrive or something like that

)
-R/RW works fine in standalone players
2.DVD -RAM
I think the advantage in -Ram is the "caddy" where the real medium is in it ... (good for liftime) so good for Data Storage ..
but u can´t read it in standard DVD-Rom Drives
3.DVD+r/W
I think +RW discs r as "cheap" as -RWs are ... I read somewhere that this would be the future standard of rewritable DVDs...
+R ? somebody who saw them ? *lol* -R will win the race
So... The best choice at this time (for me and my DVD Movie backups

) is the pioneer A03.
If u don´t want to buy a writer right now... there will be combo drives which r able to write more than just one standard @ the end of this year ..maybe earlier..