So a quick update. First, thank you all for your comments. This was a back and forth in my mind, as a number of you commented - it could be a coin flip.
Ultimately, I was concerned that if I purchased the P6 I would wonder about the P8.
In turn, I decided to purchase the GR2. I am sure there are Rega enthusiasts who would say, well won't you wonder if you buy the GR2 what it might be like if you bought the 1300G?
Maybe. Likely. I don't think the desire to upgrade ends. But somehow, maybe irrationally I have decide I am more comfortable short to medium term more comfortable with the GR2 vs the P6.
May I live to regret my choice? Probably not in this case. I don't think I was going to go wrong either way. But I appreciate the comments and experience of all those of your who commented. I took each comment very seriously.
I am currently negotiating a cartridge and optimistic about what why analog system will be in the future.
The real plus side? My son has expressed interest in my Sansui SR-717. I plan on finding some inexpensive speakers and an amp for him locally and building something fun for him. Introducing him to this hobby will be the real win.

