I learned to shoot ML flinters with the Pedersoli Kentucky, which is the shorter version of the Pennsylvania. I'm still very fond of that rifle and have lots of good things to say about it as a factory rifle and introductory gun. However, having now built and shot a Chambers York with a Siler lock, here are two of the main things I notice when I go back to my 'Kentucky':
1) The VERY small lock. Basically it's a pistol lock. I don't know why they did this, as they used a larger lock on the 'Frontier'. The flint for this lock is tiny and I rarely got more than 20 or 30 shots out of one, with knapping required after only a dozen shots or so. The flint on my Chambers lock is still going strong after 80 shots without ever being knapped! Also I notice the much greater strength of the action on the Chambers lock, which produces a shower of sparks even with a dull flint. But, providing you accept the limitations of the Pedersoli lock, which most others who've used it talk about, you can get it to work well and have a lot of fun with it - just have a good supply of flints to hand!
2)The heavy, front-ended barrel. My York is more than six inches longer than my Kentucky, but feels lighter because the barrel is swamped and it's beautifully weighted. The Pennsylvania will be even more front-heavy. But some people like this!
I personally prefer the Pedersoli design more than other factory 'Kentucky' guns, some of which are plain ugly. The Pedersoli design is generic but is supposedly modelled on an original and is broadly in keeping with a rifle of about 1810-1830, I'd say.
You'll get some people on the forum talking about the very small Pedersoli touch holes, but that was only a problem on earlier versions and I don't think you'll need to worry about drilling out the hole to widen it - mine was fine providing it was regularly pricked, like any other touchhole.
Hope you have fun with it!