The industrial ramp/soak controllers tend to be a LOT more awkward to program than controllers intended for kiln users. It's not necessarily a problem if the user is fairly familiar with the basics of control, but it does tend to be the case that the guys who use industrial controllers are usually the guys who build their own kilns and are therefore in the sub-section of the population that includes folk who are either already tech-savvy in the field of control systems or prepared to accept a steep learning curve. In particular, there tends not to be password-protection between the user and expert menus.
If you don't need/want ramp/soak capability, the Auber SYL-2352 controller in the link should be fine.
Ramp/Soak programming allows the user to set different temperatures and ramp-rates. If you are working primarily in 80CrV2, you may not need ramp/soak. I know folk who have never used ramp/soak for anything except annealing. With 80CrV2, letting the workpiece cool with the oven should probably be plenty slow enough.
The Auber SYL-2352P adds ramp/soak capability and has something of a following in North America. The SYL-5352P-S adds USB programming capability to the ramp/soak and I suspect this is worth the premium to many.
I am in the UK, where Auber do not have a presence, and have not tried their controllers.
I have used Omega CN7823 and Automation Direct Solo SL4848VR controllers for several HT ovens. These are, as far as I can tell, the same controller with different badges. IME they can be programmed from a PC using a cheap USB to RS485 converter (well under 5 bucks delivered on ebay). Both Omega and AD have very good (and patient) technical support, which seems to be pretty much worldwide. The Omega/AD unit has the ability to autotune at 4 different temperatures and to automatically select the PID terms from the tuning temperature that is closest to the setpoint. I tend to build a separate control box with plugs and sockets for the element power, the thermocouple and the door switch. The multiple PID terms means that the same control box can be used for an Austenitizing oven and for a tempering oven. It's easy to unplug the Austenitizing oven and plug in the tempering oven, avoiding a long wait for the oven to cool. The optimum PID terms for the 2 ovens are unlikely to be the same, so tuning at, say, 200 degF and 600 degF on the tempering oven and 601 degF and 2000 degF on the Austenitizing oven, means that the control should be pretty good on both ovens. To be honest though, the only time I used 2 ovens in this way, both were identical (or as close to identical as I could make them).
When I built my first HT oven about 10 years ago, I found that keeping the output cycle time short was *really* important for stability. I settled on 2 seconds after playing around with a borrowed high-end ($1000) controller and then looked for a cheap ramp/soak controller that would do the job. That's when I found the Omega and Automation Direct ones. At the time, all of the kiln controllers I could find had fixed output cycles of 30 seconds and I had determined that the "saw-tooth" temperature variation at 30-seconds was more than I was prepared to accept. 2 seconds gives much smaller saw-teeth.
If you do a reasonably good job of tuning (I find the Autotune on the Omega/AD units is excellent and tend not to mess with them after Autotuning), you should find that you don't see the temperature move by more than 3 or 4 degF from setpoint. I work in degC and seldom see a 2-degC deviation except when loading/unloading.
