I'll just add the other thoughts I had shared. Although I think RIV 1 BRs, both resort and preferred, and pretty easy at they 7 month mark most of the time currently, I don't think I'd bank on that always being true, especially for resort view - have a hard time seeing preferred view 1 BRs being hard to get given how many there are of them (65 resort, 112 preferred according to
dvcfieldguide.com). Looks like 58 of those resort view 1 BRs can be booked as 2 BR lock-offs as well, and I know those are difficult to get simply because of the difficulty getting resort view studios (I've been paying attention recently, and they seem to be pretty constantly walked).
I also think there is a good chance PVB 1 BR availability will be a lot different once fully declared. I was thinking about this recently noting that the tower rooms were immediately available for 11-month bookings to the existing PVB owners, but the tower itself is only being declared as tower specific points are sold. That means there are many more owners able to book tower points at the 11-month mark than is typical with new resorts.
And,
@VGCgroupie noted the uncertainty about restricted resorts and the fact that resale owners will only be able to book at RIV, which could further affect availability over time. Just don't know exactly how that will play out.
All of that would lead me to conclude, if you want to use points to stay at RIV regularly, I'd still buy there. PVB points, OTOH, are good both if you want to stay there regularly or if you just want to use them as SAP to stay at other resorts. And, if you're ok with preferred view RIV 1 BRs, and confident you aren't going to want to bump up to 2 BRs or 3 BRs at some point, I'd probably lean towards PVB too.