Given the amount of engineering required for drives which are able to contain helium, one would expect that the required tolerances and materials would be much

Given the amount of engineering required for drives which are able to contain helium, one would expect that the required tolerances and materials would be much better. There may be reliability advantages for Helium, but I suspect greater care and QA during manufacturing will account for most of the improvement. Also, it would be very bad PR for a new type of drive if they performed significantly worse.