Last year I converted five SSCv1 to the v3 mod during the Christmas season to try and help with flaky and stuck nodes (What was I thinking, during season??) I should have left well enough alone because I couldn't get any of the 5 controllers to work after the mod. I am very familiar with SSC setup and programming, so even after triple checking everything it still did not work. So at the time I needed them for my show and converted them back to v1 and they continued to work fine.
I have since purchased enough SSC4 to replace all my SSCv1. The v4 SSC and supposedly the v3 mod have less problems with flaky nodes by improving the data line output signal.
Since I switched to SSCv4 I have had less problems with nodes.
I am not trying to say not to do the mod, just don't go crazy and test 1 out before you change them all.
As far as the waterproof pigtails, I have begun to convert all of my SSCs to 4 core and 3 core waterproof pigtails. The ones I used this past season had no problems. Some of my older cat5 pigtails have had problems with corrosion.