My favourite A-series camera is the AT-1. Designed for overseas markets only (no domestic Japanese sales), it was a full manual camera when the prevailing fashion was for automation. There are a number of things going for it, match needle metering, modern readily available batteries, a huge shutter speed dial around the wind on lever, light weight - and it's dirt cheap nowadays.
The AT-1 is an anachronism, functionally from a previous era, in a polycarbonate body - the exact opposite of my T90. Anyone looking for a manual camera that doesn't weigh a ton or require re-jigged metering circuits could do a lot worse.
The AT-1 is mechanical only in the sense that the user sets the shutter speed. It is an electronically controlled camera with a shutter similar to the AE-1 and the A-1.
Perhaps manually operated match needle camera would be a better description. It was generally a mechanical camera with an electronic release and shutter timing system. The other AE series weren't as convenient to use in manual. That's an opinion BTW.
The minor flaw in the AE1 is the mirror squeak caused by the (plastic)gears in the mirror governor. If let go long enough, it will slow the rising of the mirror, but that has no effect on exposure because the mirror(all SLR's) actually releases the shutter.
It's a very common problem and Nikon never had a similar problem like that.
The AE series did literally get millions of people into photography.