The hardware might be the same (though I remember a report that recent i62HD Firefly from ereader-store.eu come with 256 MB RAM while the other model has just 128 MB RAM) but the software is definitely not.
You've already learned it in
another thread ... for the Polish ArtaTech model, you will not be able to install firmware updates provided here because they explicitly block it ... and they do not really care about any firmware updates themselves.