Thanks Bern.
The Ipowell has been so far my fav hack. It seems, after a few teasting, that this new version indeed incremented the quality on the underexposed areas and the banding is more controled,
I see less artefacts.
It's stable too.
The GH2 (already extremely capable but with some limitations due to factory implementations and its 8bits) is more and more operative with the work of those hackers.