A question only YOU can answer.
I'm 68 with a 25-year-old separated strap-shoulder and other back issues - the difference between 9 lb, 4 oz and 8 lb, 4 oz is pretty significant, with anything in the high 8's being my tipping point.
That said, I've got a 9-lb fretless JB that I've played for long shows before, though I prefer to bring it out for only the first set. I'll be subbing on a 4-hour bar gig next week where the fretless would be the logical choice, though the 8 lb, 3 oz PB will probably get the nod after the first or second set - 4-hour bar gigs aren't my norm these days and I can't see doing the full stretch carrying that weight.