Jez,  I prepared this for another board, but you may find it helpful.  If you want to PM for more detailed info I will be happy to assist if I can., but I don't pretend to know everything.

Philadelphia:

Center City ("CC") is the main business and cultural part of town. This area features many hotels, restaurants of all types, the area's finest museums and cultural points and other amenities. CC is best for businessmen who can break away during the business day. The lack of free parking is an obstacle to some hobbyists, but some of the hotels in the airport area also charge for parking. Another issue is that some of the better hotels require a key card to activate the elevator, so some maneuvering may be required. As would be expected, hotel prices are generally higher than in the suburbs.

Another in-city possibility is in the Penn Landing area, near the river front. The Hyatt is the nicest hotel along the river and there is nice Sheraton across Columbus Avenue in the nearby Society Hill-Old City area. You are a bit isolated in this part of town but that may not be an issue if you tend to keep to your hotel.

King of Prussia:

Another big Hobby area is King of Prussia ("KOP"). This a western suburb marked by two large shopping malls, many hotels and restaurants. The downside is that it is a trek for those of who live in CC, the eastern suburbs or New Jersey. Also, LE is supposedly most active in KOP, but you see lots of ads for ladies setting up shop in KOP. Just be careful.

Plymouth Meeting and Willow Grove:

Two other suburban areas receiving more attention are Plymouth Meeting and Willow Grove. These areas are east of KOP near the PA Turnpike and also have malls, restaurants and hotels, but less LE activity. Transportation can be a problem in the suburbs, so it would be wise to see what hotels have shuttles to either the airport or the 30th Street Amtrak train station.

Airport:

This is a favorite nesting area for ladies and hobbyists because of its many moderately priced hotels, the availability of free or cheap parking and the relative anonymity of the place. There are few amenities in the area. Travelers can get to CC by hotel shuttle, a train or by cab. There are paid shuttle services that go to the hotels in South Jersey.

New Jersey Suburbs:

The South Jersey towns of Cherry Hill and Mt. Laurel are busy hobby destinations since they are near the New Jersey Turnpike, I-295 and are not far from Philadelphia. Traffic seems to be less of an issue and hotel prices are lower. LE in Mt. Laurel is more active than in Cherry Hill and has announced an effort to stamp out prostitution in the town, yet many providers still set up shop in the better hotels. A car is a big assist, as cab service is spotty.

Be safe and enjoy the bounties of the region.