SHU93, you have had an excellent outcome. The statistics have only gotten better and better for Gleason 6 with negative margins. Search for postings by Selmer - he posted a recent abstract out of Johns Hopkins that gives some truly remarkable numbers.
Being about 9 months ahead of you with a similar pathology, I would encourage you to think carefully about the ultra-sensitive PSA test and whether you want this or the "standard" test. I had originally requested the standard test but got the ultrasensitive one. This has led to anxiety over probably meaningless fluctuations. The ultrasensitive test could give you an early indication of a recurrence, however this may be more important for higher Gleason scores or positive margins.