We just got a HVC resale and you can't use World of Hyatt (WOH), Beyond, or Juants. Basically, you can use them to book through one of their 3 collections: heritage, platinum, & experience. The Experience Collection you have to book a week at a time. There are 36 total locations between the three collections. You can also convert your points into the Interval (II).
We just got our points last month and used points that were about to expire through II to stay 4 days in Monterrey, CA. The exchange rate wasn't great for this particular booking, but did get us a free week in II. We have also booked at 2 locations (Tahoe & Escondito) in the collections they were a great deal based on what the trip would have cost.
So far, this is working out really well for us, but time will tell. I am keeping track of how much each trips lodging would have cost compared to our maintenance fee (MF).