I never worry about the dive sites that are chosen since I know they will be the best ones based on the conditions that day. I'd say to book with whatever your chosen operator is and go have fun.
Amen.
I think a lot of divers want to do the backwall simply because it has some sort of reputation as being an advanced dive. It's an awesome, awe inspiring near vertical wall, but for critters and variety of formation from slope to pure wall, I'll take Reef's End.
It's hard to find a bad dive at Molokini. Enenue drift has the grey sharks. Reef's End has whitetips, lots of critters, and you can include a visit to the garden eels if you start inside. Center Reef isn't as heralded a dive, but it has some nice plate coral and because of its well protected location, and is a beautiful example of a climax reef (the biological equivalent of an old growth forest). Even a dive on the inside of Reef's End has its attractions, such as the "Orange Grove" which is usually teeming with smaller fish.
Another things I often hear on boats are divers saying "We went there yesterday, so we don't want to go back". I guess I'm a bit unusual in that I prefer to repeat sites and observe the differences from day to day.
The crews on the better boats try hard to find the best site for the conditions (both ocean and experience level of divers onboard) each day. Rather than worrying a lot about the specific site, I just mention any particular preference I have, if any, and then just kick back and go with the flow.