No slipping, no problems other than stiff changes. But sometimes its not too bad. Just about to buy a 12mm key to check the gearbox oil?
Any opinions

How old is it? I had that on my Bravo…wouldn’t shift at all if the temp was below 2c until the engine had warmed up. Apparently a known issue with the gear selector cables. I suspect they were susceptible to water ingress with corroded them and made them stick (or freeze in the cold). As they corrode they probably do stiffen up.