I might inquire into the cost of one of these kits. Couldn't hurt to find out. What I like about this is the ability to handle extremely high pressures without any problem and the extremely small size. It would be useful for investigating inside of horns or bandpass cabs or other very close proximity high spl situations. I also like the idea that there are no moving parts, or diaphragm that reacts to physical forces with the associated resonances, etc. It removes one more source of potential variation from the signal chain.
One thing that may be of concern is the laser head. This likely uses a small solid state laser so it could be engineered to last a good long while, or it may only last a few hundred hours. Depending on use you could be replacing the diode, or laser assembly once in 10 years or every year. Also lasers do not do well with shock, rapid temperature changes and humidity usually. That could be a concern. I'm speculating. They may have developed it around a very low cost, robust laser assembly.