I liked Philly's Best until a couple of years ago. I'd only gone once or twice in a few years, but it seemed decent. Then, I went to Philadelphia. I ate them at about 4-5 places over a two week period, comparing the tops places. Oh, my. Deliciousness.
A few months after I came back, I went back to Philly's Best. Unless it was a terribly off night, I couldn't ever suggest going there if you want something similar to what you get in Philadelphia. I am not a Cheese Whiz fan - even in Philadelphia. So, I ordered provolone. But, it came with cheese whiz, TOO! Of course, I'd walked several blocks home at 11 at night before I realized this. I tried to get that goop out, but couldn't. It was extraordinarily greasy, too. I gave up and dumped it in the trash.
If you like whizzy stuff on them, and lots of greasiness, try it. As others have said, it is the closest in our fair city. If you don't want it, be careful about specifying it. I obviously didn't do it right

.
But, that brings up an interesting question for me...why is it so hard to make a good sandwich here? This seems like an automatic money-maker if you could get it close.