Ive used an aquavu HD camera through the ice at granby and was able to see down to 60 feet on some days. It was definitely dark at 60 but I was still able to see decently well. I think it depends on how much snow cover the ice has too.
I used an AquaVu 7i Pro on the ice early last year. I found different things in different places. Generally at about 60 to 70 feet you can see reasonably about 5 or 6 feet but it's not a perfectly clear picture at that depth. A few times I couldn't see more than a few feet. Sometimes the fish would swim up to the camera and look right into the lens, that's a little weird. It is hard to judge fish size because you really don't know how close to the camera they are. It's also hard to judge whether the fish are a little spooked with it hanging down there and the lighting the camera uses. My opinion is they may be a little spooked. There are things to be learned, you can see how the fish bite the jig and swim with it and how that feels on the rod. I lost one big fish when it got tangled on the cord. It does take considerable extra time to it get set it up and to keep it rotated to be on the jig, I bought the remote control pointing device which was pretty inexpensive.
I should add battery life is an issue, with only the battery it came with I'd get about 4 or 5 hours. I rigged up a spare to get more.
Overall it was interesting and I think worth the effort but I don't think I'll be doing it a lot in the future mostly because of the setup hassles. It makes it much harder to be mobile. If I know I'm staying in one place for the day and not too deep, I'll bring it along.
I should add, I don't know if the Marcum LX9 works the same as an AquaVu, but I would think they are are similar.