Hi, we provide the LCIA method pack of GaBi for the construction database, and have the same flows as the GaBi databases in the openLCA-GaBi databases, therefore I expect the results for single processes are the same. If someone is interested, we could make a test.
It is of course very different for plans / product systems where you have basically connections between process datasets; since these connections are not clearly specified in GaBi (unlike e.g. in ecoinvent) results depend a lot on how the user models the life cycle, i.e. sets the connections; consequently, you have differences for different users, even in the same software.