The main benefit of the family room (we've had one with children when they were younger and as a couple alone) is usually a lower cost for larger space. We've gotten one cheaper than a single roomette, which is hard to rationalize, and they're almost always cheaper than a bedroom. You give up personal bathroom and shower access however. On the other hand, it's fairly easy to tell when either are occupied.
There are windows on both sides and they are smaller than the standard, so this becomes a "wash" with a bedroom and its "sort-of" window on the hall side. I don't mind the lower level with its easy access to luggage and the door for fresh air at station stops. The balance is sometimes being forgotten or left to last for dining reservations (if they are still taken the same way). As seniors we're less comfortable with ladders, so usually share the lower bunk which seems larger than the one in a regular bedroom. (This may be an illusion.) While our preference is for two roomettes across the hall from each other, which gives you two lower bunks and daytime access to both sides of the train, it has been increasingly difficult to get two in the same price bucket. This frequently makes the family bedroom a relative bargain.
It's best suited for a single night, so not sure how I'd feel about the Texas Eagle all the way to L.A. despite doing it with kids in the past.