Not the OP, but have had some experience with the Arduino Opta around this time twelve months ago (Oct 24) through a professional development course I took at my local university on industrial control systems programming.

While it's nice to have exposure to PLC programming at an Arduino price point, the IDE, and PLC firmware was VERY rough around the edges. It took lots of resets and fiddling to even get the units connected over their USB serial, and you'd come back the next day and you'd have to repeat the process. Lots of "hold your tongue the right way while pressing this button". The IDE was also very buggy (though it may have improved in the last 12 months), but once you got things going, it did the job.