Okay.. having used an A3-31 then upgrading to a used AD741 (green and grey model) I can add my 2 cents:
- Benefits of the AD741
heavier machine at 550kg (excellent pressed steel, beefy cast iron top, very stable.
4 point table, as people have mentioned, this is way better than a single point table.
electronic drive - once you start using the electric rise and fall, you will never go back to the manual hand wind!
straight blades - no biggie, I had straight knives on mine.. got a custom made spiral head and swapped them over. Takes an afternoon and it’s a good time to give the machine an overhaul and calibration.?
overall, I definitely recommend the upgrade. I am lucky my machine is a 4hp single phase which meant I could still use it in my home garage.

