To Joe Average Guitar player, the CU24 is THE PRS - it's the flagship, and the model most people associate with PRS. When young guitarists out there aspire to own a PRS, that's the model they're dreaming about. They see 10 top, and birds, and incredible playability all wrapped up in one cool package. It's only once the gateway drug has been swallowed that people start looking at the other PRS models, in my experience - then they're ready to try other things.
That being said, for me, the guitar that started me with PRS (for the above listed reasons) was a CU24, and it was indeed a gateway drug to my favorite - the CE24.