I tried SNS a few times and my only problem was that I had a hard time finding high Krausen by observation. The batches came out okay with my guess at high Krausen, so I can't knock SNS - I just wanted to find a better way to detect high Krausen in the starter than looking at it.
Since the SNS experiments, I went back to the stir plate and I place an S-airlock on the Erlenmeyer flask, and watch for a peak in bubbling in the starter, which I take for high Krausen. At that point, I stop the stir plate, remove the airlock and cover the top of the flask with aluminum foil, and then place it in the refrigerator to retard any further growth. I take the starter out of the refrigerator at the beginning of brew day and let it rise to room temperature while I'm brewing. I then remove the excess liquid, add some of the wort from my batch, swirl the liquid to get the yeast cake off of the bottom and into suspension, and then pitch it at proper wort temperature.
I suppose that I could still do SNS, carefully shaking the flask with an S-airlock in place, and watch for a peak in bubbling, but I haven't tried that yet. I might try that some day - but for now, this works for me. The thing I want to do is detect high Krausen better than by just looking at it, and the airlock does that for me.