FWIW, I did my first ever status run a few months back to get me to SG for the first time. I weighed it up and decided for the ~$300 to get the 35 points to get over the line was well worth it. Especially given we're flying twice with the kids this year, so that means 4 separate QP visits for the 4 of us - kids are ravenous eaters, and the missus and moi like our booze. As for other benefits; I got an upgrade from Y saver to J Mel-BNE the other day, peak time, flight was packed - my gut is the SG helped with the upgrade as I applied v last min; got stuck in OOL for 3 hours heading back to MEL via SYD a few months ago - for me, having the lounge access was magic as the hordes outside were packed due to all the delayed flights and the lounge dragons (lounge angels!) were incredibly helpful re-schedulng the SYD-MEL leg; I've got a MEL-LHR return trip in Y+ coming up soon with a request for J upgrade, no guarantee of course, but my gut is the SG will get some segments upgraded; flown 6 Y legs since being SG and every allocated seat has been great.
So not WP yet but I've had a definite positive vibe from SG over PS or NB! :-D