How Bad Are These Seats

We were assigned seats 51A, 51C, and 51D on a Virgin Atlantic overnight flight- how bad are they going to be? We have a pretty busy day the day we arrive. I already bought ear plugs and have an eye masks with built-in headphones to try to block out light and sound. I’m glad to be sitting with my kids, but worried about noise. The only places where there are three seats together are the ones with the X’s, which say “unavailable for booking right now.” Will they become available for booking? There are a lot of those…