Hi all. Our pavers were installed 5 yrs ago with polymeric sand and I can attest that is the only way to go (if done properly) Weed free and no issues from pool water. The base for pavers should absolutely be plate compacted before and after the poly sand is brushed on, as should the pavers (the installer should use something like 1/4" luan as a buffer over the pavers to avoid scratching). As others have mentioned, the polymeric sand should be spread and brushed in, then plate compacted, then brushed in again (as the plate compacting will settle the sand between the pavers as expected). Then it is critical to lightly blow the area clean so that the poly sand is off the paver tops, and then lightly water the sand to create the seal. If done properly, the sand will create a cement like barrier that will be perfect.
As for sealing pavers, as much as my wife would prefer a glossier looking patio, we have avoided it due to:
a. the need to re-apply annually/bi-annually (you should check with your paver brand, as some have a protective coating which sealants will void the warranty)
b. Sealants often create a slick surface, which is obviously not ideal around a pool
Hope some of this info helps.