Flashcut just works flawlessly. It is almost transparent. You just connect to the Flashcut controller, load the G-code, zero things up and run.
Flashcut uses a more conservative architecture in that the software just runs on Windows and communicates via serial port with a dedicated Flashcut Signal Generator box. The Signal Generator box provides the realtime clock that is used to generate control signals for your servo or stepper motor drive electronics. Other solutions often use the computer to generate the realtime control signals. The problem with that is that operating systems like Windows and Linux were not designed to provide realtime device control. Some systems like EMC require running a special realtime version of Linux, but that realtime Linux may not support a broad range of devices such as the Wifi network card I'm using.
Flashcut also doesn't rely on legacy PC hardware like parallel ports to provide realtime control signals. Parallel ports hardware is almost extinct. Flashcut uses a simple serial connection to communicate with the signal generator, and I've found it works fine with a USB to serial adapter. So just about any PC with a USB port should work.
I have a 4 servo Flashcut system driving a 4-axis Taig mini mill. The Flashcut software runs on an older 333MHz P2 IBM Thinkpad with a WiFi card. Because it's all just running under Windows 2000 and uses the serial port to drive the Flashcut controller I'm able to just access the G-code files directly off my CAD/CAM workstation. Also the fact that it's all running on my Windows network makes it easy to do iterrations when experimenting with getting the G-code just right.
The servo tuning software that comes with Flashcut works quite well. It requires a second serial port for feedback from the servo controller. I have that running through a USB-to-serial converter. I've never seen much discussion of servo tuning based on my limited experience with this system it seems like an essential part of putting together a servo-based CNC system.
Of course if you are running steppers that part is not necessary.