I own this one, I was just playing it
The biggest differences between this and the core so far as I can see are the scale length, and the top carve. I think the 25" works well and under your arm the bevelled top feels just fine. I wouldn't let the pickups be a deciding factor over the scale length and neck feel tbh...
This is my favourite guitar. I have spent more on others, I also have a PRS CE22 but this is the one I consider my 'best'. The neck is lovely, it feels like it was carved just for my hand. The bigsby works fine, no tuning issues whatsoever even with standard saddles which I thought I would have to replace. The finish feels nice and never sticky. The board is really dense feeling, very nice piece of timber. Guitar sustains well and is very snappy and loud unplugged.
The pickups are fine. I haven't played the core ones so can't compare, but I think these just get a bad wrap because of where they are made, they stand up well on their own. They're articulate and Gretschy, definitely a lot of character and I found I rather like them which is why I still have them - like the saddles, I was prepared to flip them. They're not hot pickups by any means, but they're punchy - the coil taps sound alright too with some dirt.
These pickups are very sensitive to height and pole piece adjustment, so keep that in mind. They sound great through a very middy loud amp. And I beg to differ about them not being metal - this sounds wicked in C with gain. The first time I saw a Starla it was in the hands of Brent Hinds from Mastodon