I think like most agricultural products, barley flavor is influenced by climate and soil. Also, variations between maltsters can influence flavors. A good way for you to learn the similarities and differences between base malts is to make a Single Malt and Single Hop (SMaSH) recipe, changing only the base grain. Then you can use that experience to help you make the best beer you can in future batches.
Worst case scenario is you make a nice series of SMaSH's, and have to drink them. :-)
If more of us valued food and cheer and song above hoarded gold, it would be a merrier world.
--J. R. R. Tolkien
"Revvy is so powerful that he can tell his recipes what the gravity they should be at any point in his brewing process and they immediately go to said gravity." - Shep