HDVdiver already shed lights on most of the triviality.
I really do not understand why you write so authoritative comments.
I could be mistaken as a fan boy but I really think to each to their own. I have several friends who are happy with the 7D and 60D. Actually for video IMHO the 60D is better because has a flip diplay which makes really the difference shooting on land. As already told you is mainly a lock-in matter or put simply: the pros use Canon so I do the same.
I over react to your sentences because are nearly straw man arguments. On the breadcumbs over the page I read:
Video and Film > Video Gear and Technique >
So Would be nice staying IT. We are speaking about video, underwater video. I wouldn't imagine to argue against a 7D or a 60D speaking about photography but here we are speaking about video. And it's a matter of fact that a GH2, out of the box is equal or better than these canon models. Far better of a 5D MKII. Once hacked, the GH2 is far better of the counterparts. Of course, the final choice is still a matter of personal preferences and tons of other considerations.
You did not bother to ask to OP which videocamera he has (we only know he has an Amphibico housing) nor which kind of shoots/dives he usually does. So I really get annoyed reading your reply. The question could came from Howard Hall or a casual shooter with a bunch of money.
So the correct answer would be: we all agree that today if you want the all around quality of Rafa Herrero videos a proper videocamera is still unbeatable but for most of all a DSRL/EVIL camera could do the job. Out there (and here) is full of pixel peepers but the truth is that for a good video you still have to tell the story.
If the weight is the main concern then a GH2, NEX-5, NEX-7 could be viable options as well the Canon 7D or the 60D. IMHO a FF it's not worth it. Just browse Vimeo and see how many deep video are shot with a NEX-5.
Coming back your sentences:
The issues with M43 is that one has to use a hack to get good quality
False, and to apply a hack you need a couple of minutes. Most of the users bring with them several settings ready to be loaded. Applying a hack it's the same procedure to apply a original firmware update.
DR and ISO performance isn't up to par.
False. Nobody uses 12800 ISO for a real job and both the camera shows noise artefact higher than 1000 ISO. If you are a pixel peeper the internet is full of "A Vs B" video.
only if one buys the fast SD cards and hope they can handle the speed needed to go 150mbps to achieve that extra resolution.
False again. You can go from 44Mbs to 150+Mbs based on your needs. Only the most extreme hacks needs the 95Mbs cards for spanning but ALL the hacks works with the classic Sandisk Extreme 30Mbps.
BTW the GH2 resolution stands to the Canon C300 (According to Philip Bloom)
Plus the lens choices for APS-C goes from circle fisheye to FE macro with the bugeye lens. Something neither FF or M43 has.
Maybe it's true for land shooting but for UW Video is false. (Again: please stay in topic with underwater video).
Looking at the current Nauticam and 10Bar housing port offering you are plenty of choices:
You need really wide? You have the extreme Lumix 8mm or the the rectilinear zoom Lumix 7-14 or the Olympus 9-18
Just wide? The wonderful Oly 12mm f2 that accomodates in the same 8mm port (saving $)
You need macro? You have the Leica DG Macro-Elmarit 45mm, one of the best macro lenses out there.
Then you can use the 14-42mm or the 14mm.
Then there is the final icing on the cake:
I prefer educating people to make their own decisions based on their needs, so they can't blame anyone but themselves!
Unfortunately you forgot to ask to the OP what are his needs.
PS
You need transcoding with 5DtoRGN only with some ... NLE. E.g., with EDIUS you just throw the files in the bin.
Bye
--
Davide