With the ST-122 you have to be a little more careful, or use a carrying case or bag. The Peterson protects the display and buttons better with its clam shell case design, so it's better for casually throwing into a gig bag. It's sized better for fitting in instrument case compartments, and it's lighter in weight (although that may change with the new aluminum case model). The Sonic Research tuner is a little faster to switch between 12TET and sweetened tunings. There are a few other differences worth mentioning. It's just a question of which display paradigm works better for you. I can tune as fast on a Peterson as she can with the ST-122. I'm more used to the Peterson display because I've been using them for years now. She got the Sonic Research ST-122 and is very happy with it.
![tube strobe tuner dial not moving tube strobe tuner dial not moving](https://www.pro-led-lighting.com/photo/pl14057300-150w_powerful_strobe.jpg)
My Significant Other is a fiddler, and she could just never get the hang of using my StroboFlip, or my original "blue brick" Peterson VS tuner. This helps with any tuner, but it's especially important for the Peterson tuners in stabilizing the display while you're tuning. With my StroboFlip, I pick the tuned string with one finger, while using my thumb and other fingers to damp the other strings so they can't go into sympathetic ringing. The display can be jittery if it's reading harmonics from other strings. The Peterson tuners are very sensitive to the overtone series, and they show it (in groups) as part of the display "wheel". I think one problem people run into is not damping the other strings well enough.
![tube strobe tuner dial not moving tube strobe tuner dial not moving](http://cygnusobservatory.com/blog/wp-content/uploads/2013/02/MG_9885.jpg)
I think it takes a while for most people to get used to the display, and some folks never get comfortable with it. Is the strobo flip like the strobo stomp display?Yes, they're the same. Oh yep yu are right it is a true dial spinning, not a digital display.