As I have an e93 I just read the test results to see if they are as bad as people are suggesting.
In short the e93 results for head on collisions were about the same as the e90 so good news on that front. It was the side impact that was worse.
Since the e92 has much the same door design as the e93 I would suspect that any e92 tests would show similar results. On that basis one could conclude that in an accident of this kind the e92 would suffer a similar outcome in terms of damage and of course injuries etc.
On the other hand because of the additional rigidity built into the e93 sills and floorpan the e92 could suffer a worse outcome to the e93.