For DVD @ 2.4X, I get 23 - 24 minutes. And yes, consider you're burning 4.38GB of data it's actually really fast.
For 700MB CD @ 52x, I get 2:30 minutes
Get a dual format DVD writer for $195 so you don't have to think about which one to get. But then again, you can always bring DVD+R and DVD-R media w/ you when you go DVD player shopping. DVD+R writer costs $159.