Southfield is central. I don't know it's best. It's just between Novi and Troy that you have an easy shot to either, and downtown.  

I think downtown higher-end hotels are fine, but I'm sure there are ladies that won't go down there. The casinos are probably a good bet.  

I'm sure others will have more informative comments... I avoid downtown too just because I'm the guy that will make a left instead of a right, or get a flat in the wrong spot

Southfield is a little low end but good for high volume girls but you still need to be careful due to LE

Detroit is a PITA!  Less than 10% of clients I would imagine are from the city, the valet etc of the casino hotels is a pain.
Detroit is not like other Downtowns, it is just starting its comeback.  Very few people over 30 live down there.

Novi is always a nice place.
Troy is good as well but I imagine LE concerns exist there.
There are some good hotels are the airport.

I think Novi is the most central of the areas I see adds.  When I see people visit Novi then Southfield I laugh as anyone who will go to one will go to the other as they are 15 miles max apart.