Greg:
Congratulations and I'm happy about your results. However as others have said...you need to keep an eye on this. THe 4% is definitely worrisome and, frankly, an 8 core biopsy is not state of the art...too few samples.
I would recommend a PCA3 test along with your next PSA. Depending on that result you may want to consider another (more inclusive) biopsy.
Tudpock