Order or core versus earlier sets?

[Drinkdrawers]

My friends and I are finishing Rise of the Runelords soon, and we have Skull & Shackles to play after that. 

Christmas is coming and I want to get these friends more Pathfinder. I'm sure it would be fine to continue on to Wrath of the Righteous next. 

But now there's this core set thing. 

Does it make more sense to get the core set and tweak these older boxes to use its rules? 

Or will it be better to finish all the other sets before going Core?

Thanks!

[Axoq]

If you know you're going to play them all, I'd suggest playing all the pre-Core sets before advancing to Core. The change is radical with the move to Core. (Play them in order, and you can see the game evolving before your eyes.)

If you're not a completionist, I might recommend going to Core straight away. I love the changes in the new set.

[Longshot11]

Forum consensus seems to be that Mummy's Mask set (which you don't even mention) is the best pre-Core PACG set, so I'd recommend that one (if you don't intend to play them in order).

As for Core, YMMV - check the forum and this Conversion guide - https://paizo.com/paizo/faq/v5748nrupch3i#v5748eaidgsjq

- to get an idea if it would be your cup of tea. There are a few small good changes and several big ones that are... controversial, to say the least. For big parties, in particular, the game is rendered a lot more unforgiving and that may tip your experience from fun to frustrating, depending on your tolerance.

[Matsu Kurisu]

Core + Curse is my favorite
Mummy’s Mask second

[etien]

Yes go for curse then core.
If you still in needs do the last 2 pre core, I find skull the hardest to get into as the boat rule set never made it to me.