Yeah we tried it. We used it for a while in our machine shop until the unit broke and we didn't have the budget to replace or repair it. That was at least ten years ago.
It is not a substitute for thermal stress relieve to improve fatigue resistance, nor is it suitable for knocking down peak hardness in alloy steel heat affected zones. It's only marginally effective in stabilizing weldments prior to final machining. To my knowlege, no codes describe its use as a requirement or as a substitute for thermal stress relief. You need to search your codes to see if it's prohibited.
The process is heavily touted with plenty of "satisfied customers" and lots of testimonial evidence. At least that's the way it was fifteen years ago. I'm still watiting for a PHD thesis proving the metallurgical distribution of dislocations coupled with rigorous residual stress measurements and studies that use rigorous fatigue and fracture mechanics data to prove the process has a metallurgical benefit. Our chief metallurgist at the time labeled it as "psychological stress relief".
We did a one time test by welding a steel cylinder (I think it was somewhere around 30 inches in diameter and three quarters inch thick) and cutting it into three pieces about a foot long. One we thermally stress relieved. One we vibratory stress relieved and the third was as-welded. We machined the ID's to a "final dimension" then machined the OD's. IIRC, the untreated cylinder went out of tolerance 0.010 inch, the thermally stress relieved cylinder went out 0.003 inch and the vibratory stress relieved cylinder went out of tolerance about 0.006 inch or so. (We didn't do a full statistical evaluation. This was a one time, one data point cheap and dirty test.) In other words, it's better than nothing, and not quite as good as thermal stress relief in helping to maintain tolerances in a machine shop operation. You'd have to know what kind of tolerances to which you're working and understand what it takes to meet them. But if you need to work to tight tolerances, there's no substitute for thermal stress relief if you can use it, or "sneaking up" on the final dimensions with a combination of rough and final cuts using appropriate tooling consistent with your need to control your processing. I'm pretty sure we continued to use our standard machining techniques even with the vibratory stress relief being done on the parts. So, it didn't really save us anything. Thus, when the machine broke, there was no incentive to get it fixed.