Well, in that case I would buy it anyway, you can always add the Set Top Box Controller for a small incremental cost.
Also, if you have the opportunity to test the AVANT before you buy it, then you can always go into the Service Menu and you can see the version number and if it does not have the version stated, then it is not installed. Also on the back of the TV there will be two (if it has a STB-C) very very small blue/grey labels showing the software version number of the TV itself and the version of the STB controller.