High Availability, User Profiles, and UPRE

I'm setting up High Availability using Metalogix Replicator to mirror the Content DBs. There's a Primary (current production SP2010 environment) and a Secondary environment. Both consist of a WFE, SQL, and APP server.

User Profiles are set up on both. I created the Secondary environments by copying Profile, Social, and Synch DBs from the Primary SQL server, and creating the UP using the same DB names.

Since then, we have created new Audiences and new User Profile settings.

So the two choices are:

1. Manually update both environments.

2. Use UPRE to keep them synchronized. I've looked over https://technet.microsoft.com/en-us/library/cc663011(v=office.14).aspx and it seems like a good solution.

I'm not sure whether to use synchronous or asynchronous. I was also wondering if anyone has experience with setting this up, and if there's any chance that I'll mess up my current Primary User Profile service/synch by using UPRE.

Has anyone been down this road? Is this what I'm looking for?

Thanks,

Scott