No experience here. But there are tradeoffs.
Having it mobile means a few more things could go wrong, but those things are all unlikely events anyway, and the design looks solid enough to avoid most of the potential issues.
The reason they stated in the interview for making it mobile was to enclose the two mirrors nearest to the laser. Which is an EXCELLENT move, especially for making the whole thing usable and serviceable by non-technical people.
Cleaning mirrors is a delicate process, primarily because of how tiny they are. You will have a constant fear of crushing or dropping the little disc. But in this setup, there is one window to clean on the far end of the mobile arm, and another at the side of the cutting head. Air assist keeps the lens clean at the bottom of the cutting head.
So, instead of 3 mirrors you may have to clean with optical cleaning equipment (special air blowers, special cloths, and special chemicals), you have two windows which dan says you can just wipe off like someone would their eye-glasses.