If your stepper motors are tuned correctly, and are not being overloaded for the job at hand, they are very reliable. Missing steps can result from poor tuning, electrical noise, or not up to the task for the load on the cutter.
However, if things are set-up right, you could mount a 1" travel dial indicator at the extreme left or right X position of your job, and set it to zero. Then put an M1 in the program when the axis reaches that "0" point, and the program will stop and wait for you to hit cycle start to continue.
There are Hybrid Stepper systems, and there are Servo systems with encoders. It all depends upon your wallet, and needs for the job.
The newer digital stepper drivers have motor tuning capability through a software program in real time, that offer the best stepper tuning possible. The program is called "Protune", and shows a graphic on a program screen, connected to the driver by a RJ45 connector and an XP computer serial port. Look on the Leadshine site, or CNC4Pc site for more info.
John