20 Amps just gives you 5 more Amps before the breaker trips. Since is it easier to avoid ground loops, if everything is plugged into one outlet, having that outlet be able to handle all the gear can be a plus.
If you're having new ones installed, there's not much reason to not install 20 Amp breakers. You may need a slightly larger gauge wire, and 20 Amp outlets have a the ability to take a plug which has one leg turned 90 degrees. This difference in price in the breaker and the outlet will probably be less than $10 for each pair. The copper wire might end up being the largest cost, if you need to go up a size. For short runs you won't even notice that.
