I have both the Operator and Elite Operator.
With the caveat that "every rifle is a enigma unto itself", my EO is the go-to gun and functions flawlessy with the RRA polymer mags (which appear to be identical to the Thermold) and steel FAL mags...inch or metric. The Operator is a bit more finicky, sometimes choosing to lock the bolt back with one round left in the magazine on the steel magazines. Haven't run the polymer much in it.
At $1,100 BUY IT!! The mag fixes are simple. If you have issues, come back and let us know what they are and we'll walk you through it.