upgrade advice from a Linn LP12

Jim, I think you have asked a question that depends on your definition of "improvement".
Your current TT is very good, IMO. I was faced with a similar question last year, and went the Linn upgrade route with a new bearing, sub chassis, power supply, base, etc.
I now have a MUCH better TT; that is IMHO competitive with other TT's that are multiples of what I spent. Therefore, I would suggest you look at the Linn upgrade path as your first option.

If you think your Linn is good, then just go listen to other rigs to see what you like. It shouldn't take long to find something better.

Bpoletti, when was the last time you listened to a current spec LP12??
Your comment tells me that it's been a while, LOL.