You can also call CRO to check on AP or code rates, they are sometimes better than the 25% discount member services gives. You also get full housekeeping for those nights. You do have to pay 1 nights deposit in advance for CRO reservations. CRO rooms come from the cash pool of rooms, separate from the points pool.
The member discounted rooms through member services come from the points inventory, so you do not get full housekeeping for those nights. They are added to your points nights when figuring housekeeping dates. You do not have to pay a deposit but they do ask for a credit card # to guarantee it. If you cancel 5 days or less, they charge 1 night to the card.
I've done it both ways the past 2 years, paid for weekend nights either through member services or CRO. Both worked well. An OKW 1 bedroom is 48 points per weekend night in May, I paid about $300 a night, about $6.25 a point so it doesn't make sense to rent points for weekends (unless you can find someone really desparate to rent points).