Hmm. I can't imagine that such a thing is a huge problem. It's not all that different from Sony's "Emerald Green" CFA that they introduced many years ago (they called it RGBE). Their "Emerald" had more blue in it than the standard green. Based on all the sample images at the time, it actually produced better color accuracy...but it would be the exact same thing as your describing with the 7D.
When you have two similarish but different greens a typical de-bayer will get tricked and create maze patterns.
I also can't imagine that it would cause a loss in resolution. I mean, the crux of any bayer demosaicing algorithm is interpolating the intersections between every (overlapping) set of 2x2 pixels. Because there is reuse of sensor pixels for multiple output pixels, there is an inherent blur radius. But it is extremely small, and it wouldn't grow or shrink if one of the pixel colors changed. You would still be interpolating the same basic amount of information within the same radius. I remember there being a small improvement in resolution with my 7D between LR 3 and 4, and things seem a bit crisper again moving from LR 4 to 5. I suspect any supposed loss in resolution with the 7D was due to the novelty of Adobe's implementation of support for the 7D, not anything related to having two slightly different colors for the green pixels. The quality with which LR renders my 7D images only seems to get better and better with time and each subsequent version, so as Adobe optimizes their demosaicing implementation, any inherent error is clearly diminishing. BTW, there is no way anything Adobe has ever done that could possibly "knock off 1-2mp worth of resolution" from the 7D.
Well if you compared the first ACR that handled the 7D, which also mazed a lot, the version that came out right after where they fixed the 7D mazing, there was a subtle lowering of micro-contrast. My 1-2MP was just a wild guesstimate. (1MP off of 18MP really is not much when you think about it, especially what it would mean for linear resolution change, although maybe calling it 1-2MP was overdoing it)
Ah, I see what you are saying. Well yes, you do need to properly integrate the specific bayer pattern. If there are two shades of green, that does need to be taken into account. It won't reduce resolution, though. As I said, spatially, it is the exact same source resolution, use of an alternative green is not going to reduce microcontrast or anything like that.
DPP will produce a fairly jagged result, ACR/LR produce a very clean result. Based on the sample below, ACR is actually sharper and supports even finer detail resolution:
It depends, I find ACR can get pretty jaggy in some cases, at least with non 7D cameras. I do find I can pull a bit more finer detail with it than DPP though.
I'd like to see some examples of ACR being jaggy with a camera that has an AA filter. If your camera lacks an AA filter, then certainly...but a sensor with a proper OLPF produces remarkably sharp results with LR's demosaicing algorithm. Sharper than DPP and most of the demosaicing options in RawThearapy. Some demosaicing options in RawThearapy operate more on a "super-pixel" type demosaicing algorithm, so you lose output resolution, but you gain color fidelity and lower noise...kind of hard to compare LR with those options.