Brian H.,
Manni's is WELL WORTH a go. While they have some tree issues, I certainly wouldn't characterize them as out of control. I played there late last Fall and didn't feel constricted by tree growth(and our company oftens takes them down for a living). The course was quite firm and the greens were screaming fast. This preasentation can be challenging there, as the course has many holes in a valley setting. That said, it is usually in fine condition and if the rains have been gentle, can provide some wonderful play and approach the quality of the other four Flynn courses you have on the docket.
IM me your contact details and we can see what might work in to your schedule.
Jonathan,
Philadelphia Cricket, as a club, is about as well-run as any in the Philly area. They are progressive where they should be, and have spent serious money to re-invest in their courses and property assets. Dan, the superintendent, is a sharp guy who really brings it when it comes to maintaining and improving the presentation(s) on the courses. The Flourtown 18 and St. Martin's 9 holer have some great GCA, with work ongoing to refine and reveal more of the classic bones of each. A day there would be time well spent. Hope that helps.
Cheers,
Kris