Would anyone care to comment on what the downfalls of the commercial gyros were? Is it precision or time-lag? I know I can't get specifics, but I'm curious in

Would anyone care to comment on what the downfalls of the commercial gyros were? Is it precision or time-lag? I know I can't get specifics, but I'm curious in general what is different in this application that commercial gyros were not capable. Any info would scratch my itch! Thanks!