Uneven grind. Cord exit not well thought out. Could use rubber feet so it doesn't slide around on the counter. Front button pointless because you have to hold the grinder firm to use it... just use the timer knob.
I've had the Maestro for quite some time and it has served relatively light duty in my household. I was pleased with the machine at first, but now I find huge variance in the grind. I'll set the machine to drip for my vacuum pot, and I end up with a mix of grinds anywhere from moderately large flakes to powder. The fine powder ends up clogging the vacuum pot. In fact, it looks like the fine powder is responsible forslowing down our drip pot substantially also.
To be worth the money I paid, I was expecting a grinder that was very consistent for drip, vacuum pot, and moka pot coffee. My grinder is not up to the task.
Unfortunately, I haven't kept a close eye on the performance of the grinder. I have a super-auto espresso machine which I use at home most of the time. My SO uses the grinder for drip. My espresso machine is out for repair, and now I've been using it again for the last few weeks. This caused me to notice the problems. I do remember the vac pot started stalling only a year after we bought the grinder though (Santos with either glass rod or filter disk).