All of the comments here hold weight and pretty much sun up the issue.
Used the Microvib pretty extensively in the past and found it pretty good. Really good at spectrum analysis and finding things causing harmonics.
I was lucky enough to spend some time with John Beach the developer and president of the company.
Only caveat is if you don’t understand the theory you will end up going down a rabbit hole.
That being said it has a lot more uses than just T&B. We used it mainly on AS350/355.
Great for drive shaft balance and finding things like duff starter/generator bearings, Arriel engine balance and HMU static droop, Nr out of whack etc etc.
Their website has a pretty good section on training and theory and you can get better results than other systems.
Bottom line is a lot of bang for your buck with the caveat that you need to understand what you are doing and why as previously alluded.
Would more than likely buy one again.
Although be careful these days as some AMM’s call up a specific brand and model which may be an issue.
2p.