Can I use UAG to isolate my customers' portals on our extranet?

Question

It sounds like the best practice for isolating different customers on an extranet is to use separate site collections for each customer (as is recommended in every answer to this question). If I have UAG available, I'm wondering if it would be a suitable replacement. I have two questions regarding this:

1. Could UAG provide the same level of isolation without the added complexity of maintaining over 200 site collections?
2. What drawbacks might this have (e.g. not being able to turn on/off services on a per-customer basis)?

Answer 1

UAG is not going to "re-architect" the way SharePoint works. UAG will provide you with an added level for Defense in Depth, by forcing authentication prior to hitting SharePoint, as well as allowing you to NOT have your SharePoint servers directly to the internet via reverse proxy. You still need to define your security boundaries inside SharePoint per Site Collections, Web Apps, or even Farms.

Depending on your separation requirements, if information leakage is not a critical factor you can utilize sub-sties and audiences and just take advantage of the native security trimming. If you want separate security context's you are back to the three methods above.