Random seek performance is a good way to see how fast your array can find data. Bonnie++ by default spawns four process that start seeking on the volume. This is convenient because the system is a quad core processor. This ensures that the arrays will be hit in a more realistic manner from a server oriented standpoint. If you are setting up a server for your media, this is a good benchmark to pay attention to.
The results again are fairly predictable however it seems like adaptec may have implemented some enhanced seek performance in their raid10 configurations. Raid5 finally starts showing some benefits other than total volume space as well. Random read and write seeks are important primarily for arrays that could be under heavy IO loads or concurrent users. For this reason raid5 makes a good choice for heavy IO servers that focus on concurrency and size rather than brute force speed.