Make sure you get the software and whatever licensing goes with it. I *think* Amada is good about giving software to people who have lost it, but that's the main downside to a cnc brake. Also, repairability may be a challenge if you bought it dirt cheap and don't have any repair budget.
Do you mean mechanical or manual? Mechanical brakes use cams to shove the ram down. You can have non CNC (manual) brakes that are hydraulic. Mechanical brakes will produce more tonnage than they can handle and break if you set them wrong. Hydraulic brakes will not go over their max tonnage, though that can be enough to squish or split tooling.
CNC brakes are way better though. You have to have the competence to change settings, calibrate and tram things, and enter in tooling libraries and make part programs. But you can make a part on a CNC brake in less time than it takes to crank all of the wheels on a manual brake.
At work I use what is essentially a manual hydraulic brake with a factory CNC retrofit. The backgauge and ram are CNC, but the R axis and finger X axis positions are manual. I hate going to the back of the machine and moving fingers or cranking wheels. Typing a number (or pulling up a program) is so much faster.
