From our experience, Chairman Status gets you 3 things, 1) 30% discount at <60 days out for reservations (I've used this about a dozen times), 2) ability to reserve some MVC resorts (not Vistana) at 13 months (I used this once for the BI), and 3) Titanium Elite BonVoy status (we have gotten a few room upgrades and free water, but not that useful for us).
I would estimate that Chairman status for us to be worth about $1000 - luckily we were grandfathered in with our M-resort resales.
Oddly, in our last 3 Owner Updates, they have not really tried to sell us anything. The last one by video lasted 20 minutes and received 400 CPs.
Some VOIs offer a good rate on CPs (MF/CP plus some portion of the Abound fee depending on usage), but WPORV is not one of them.
It would be interesting to see what the current MF/CP is for Vistana.