The software updates on these units are only going to be as good as the skill level of the programmer(s) working on it. If the top or lead programmers are weak and not thorough, then there will always be glitches with every update.
Also, to produce the most efficient and fastest running code takes programmers with years of experience. To produce the best error-free updates, you need the best programmers you can find.
The people in charge of hiring and managing these programmers at Humminbird may not have a clue to these facts.
Just a thought.