50# and under I was using the RP/JC knot. Now that I am a little more proficeint with the Pena knot. I feel more confident with that knot. Learn them both and see which one you can tie better. Take a piece of mono or flouro and tie a RP on one side and a Pena to the other. Then test to see which one breaks first. Go with the one that you tie consistently better
Both the RP and Tony Pena knot will get the job done and can be tied under 30 seconds. When I was in Panama a couple of weeks ago I had deckhands tell me that they've been using my knot for years with never a failure. That has been my experience also-whenever you're hung-up or lose a big fish the hook may straighten, the leader may break or the hook knot will fail but the Spectra to leader knot won't.