For most microscopes you can buy eyepieces for glasses you don't have to switch anymore.
The only problem I have is the minimum 5x zoom, it is just too much for normal P&p IMO.
3x would be ideal.
If I would build a manual P&P I would choose that multiple pcbs can bevfitted since looking up where to place the parts costs time. Doing the same parts for multiple pcbs after eachother makes it faster.
Right, I take my glasses off when using the microscope. If you can get your eyeballs up close to the eyepieces, you get about 2X the field of view. With everything blown up, uncorrected astigmatism is not a concern. I'm massively nearsighted. When doing full assembly manually, I pull out the required number of parts next to the board, and then mount, say, all the 1K resistors at one time, then move on to the 10K or whatever. I do a lot more inspection/rework than assembling boards completely by hand, so that doesn't take adding parts, just checking for bad joints and solder bridges. Also, in some cases, I can line up a bunch of small boards, and put all the R1 on every board, then do R2 on every board. This saves me time by mounting all the similar parts, not having to check the BOM over again for each board.
Jon