Linn LP12 turntable

The top 3 polarizing/contentious have now been mentioned in the thread.

Linn, Rega and VPI.

Hopefully, the OP follows his ears/wallet to his "Goldilocks" table.

Just don't cheap out on the cart and phonostage!

The road to a satisfying analog rig can be a long one. As you said, many audiophiles own, or have owned, an LP12. Like everything else, there are always conflicting opinions. In any case, the LP12 will be a big step up from your Project table. Considering the past owner’s investment versus the price to you, do you really have a lot to lose? Will you look back later and regret not buying it?

If the linn sounds very good on a good  system, you know it’s capable of doing so which is all that matters. Any system is only as good as it’s source. 

If you take $2400 cash to your hifi dealer and ask politely, will he grant you a week's in-home audition?

@signaforce you said "But not sure what listening at the dealer might do. They have my speakers, but a different cartridge, electronics & room acoustics. Would that not be too many variables?"

and you also said "a P10, the table I had planned to purchase."

Wouldn't the same variables been in play for the Rega or were you going to buy this table without auditioning?  I do agree with the above post that if the Linn sounds excellent in the store then at least you know it is capable of doing so.  Good luck with your decision which ever way you go.