It’s horrible. A maintenance nightmare. Black Hole is the better of the two and I can’t stand that game either.
Don’t get stuck on a game that “has two play areas”. It can help some games but don’t assume a game is better or “well designed”, just because there is an additional level.
Flash Gordon is the far superior game on the list thus far. I hate to shoot down others but the best designed Williams two level is actually Jungle Lord. The sound is annoying but the rules are so much better than BK, SF, or (gasps) Pharroh! The gameplay of the other Williams split level tables grows old after a couple hundred plays.
Hell, if you can find one, Barracora is a way better game than even any of those classic Williams.