It's...pretty bad. But if you like Whitney Houston (like me) then you'll probably be able to tolerate it. Just keep your expectations LOW. And it'd probably help if you can go with friends so you can have a laugh about it later. Because it's almost turkey-bad.
I kept hearing that Heather Headley was amazing as Rachel. I wish I had seen it in London. And when I saw it in NJ Deborah Cox was out so that may have skewed my perception. But it's just not a very good show. (Yes, the shirtless chorus boys are nice to look at though.)