I always like one of the decent hotels near the airport. Easy parking etc. The disadvantage is it is slated for your. Enter Cityis the least convenient for me but it has great restaurants and --of you every have time-- great museums etc.  But parking is hard and it is not always easy to get in and out of town.  King Of Prussia is a compromise as there are good restaurants stores etc and it also better access than in center city.  Plymouth meeting is easy park accessible to most areas but a bit isolated.  
Theater advantage of Center City is that if your clientele works in center city it is accessible to them.  

Have anice trib, I love your website.

I appreciate it and the info is helpful too!

This has been a debate topic that has no clear answers.  Guys from the western suburbs say KOP is best. Guys from New Jersey and Philadelphia say Center City or the airport and that KOP is too, too far away.  So you are always going to get varying answers.

If you will look a few post down you will see that I posted an area summary that may be helpful to you (I am too lazy to cut and paste it here).

For me, I prefer Center City and I rarely go to KOP (like twice in 10 years) , but I will go to Plymouth Meeting. I also don't like the airport area even though it is very convenient for me.  

I find Center City Philly (CC) to be the most difficult city center in the country to enter and exit easily.  I am bias to KOP as I am on that side of town but i cant imagine why anyone who did not live in CC would want to go into CC.  I would rather drive from one side of town, AROUND CC to other side of town then to go in to CC.  Just my 2 cents.