I have one at home that I bought impulsively from a friend.
I have not really gave it an honest go, plus I am a horrible front squatter to begin with, but here are a few of my observations.
- you really have to position it properly on the bar so it will sit right on your shoulders - It really takes the stress off of the front of the neck and collarbone - bar tends to sit a tad higher on this thing obviously - if you let it sit too far on your delts, your delts end up taking a bit too much stress - I tried it with bands once and it was really neat
Since I plan on never front squatting again for the rest of my life if I can help it, you can have mine if you want to pay for shipping...
Personally I love it. I am not anywhere near your league in weights. Up until a little more than a year ago all of my lifting was done with 1" weights (bought 25+ years ago -- when that could be decent metal). I squated using ironmind cambered bar (buffalo bar -- used to be available in 1") At my first competition I bombed out twice with 330 lb twice. On the third time I was so thrilled I hit depth, I racked before being told to. one of the refs was kind enough to tell me that I was leaning too far forward and basicly doing a good morning for my squat. I was embarrased by this weight (I squated 400 lb 40 times for my 40th -- with 7 sets -- again, I know not significant weight here).
I then bought the sting ray. First time could only do the bar -- a couple of times. but it has greatly improved my form. I am now easily squatting 400 at correct depth -- and have hit 425. I can only make 200 with the sting ray -- but form wise it has been very helpful -- much better for me than box squats.
Because of my schedule, I have not been able to compete very often. I am looking forward to one now that I am better in form.