I'm not sure you should put too much weight on this, but three times now, I've almost entered the credit card number, and I've been seriously considering the JVC. Gary Natrass swears by the Panasonic and as my needs are shoulder and tripod, I pretty much excluded the EX. I never got to try them side by side, but one at a time a few weeks apart, and my conclusion was that the JVC is the one I have at the top of the list. The camera I was able to try wasn't the 790, it was the 750, and it came through the theatre venue I do lots of work in - providing images to an on-stage screen. The lighting was quite typical and not excessively bright and the image quality was great - with the lens at a sensible f stop, meaning no focus problems. The 750 and 790 have very similar spec, so I nearly made the jump. I didn't buy in the end simply because the last few jobs that came in were for SD, so I've had an extra 6 months out of my old 1/2" JVCs. At some point I'll have to make the move, and it will be the JVC - but knowing my luck by the time the funds are available again, there'll be a new one!
I read the same things about low light, but what I saw, with no gain was grain free and had vivid colours.