I have both the Safeguard and the Grigri+. I got the Grigri+ because I couldn't get the Safeguard to work as smoothly as I wanted. The Grigri+ works very smooth. Now when I was tying to get the safeguard to work smoother I bought several different ropes. I have Predator, Oplex, C-IV Canyon , Sterling HTP and others. I've used the Grigri+ with the Predator rope and I think it was the C-IV Canyon. I noticed the Grigri would creep down without weight on it on the Predator so I threw a Cong duck on it. I left the Grigri on the rope but moved it to a linemans loop. I didn't notice any creep with the other line. Still playing to see what I like best. I have tried the figure eight with an auto block but I don't really care for it.
I was climbing with a tether and then switching to my rappel to desend but realized that if anything happened switching to my rappel line would be a royal pain so now I climb with my rappel.