You can also use them to buy tickets, or mix itineraries, on most any medium and large non-*A carrier worldwide; I've done mixed itineraries with them in all parts of the world on UA/BA/IB/EK, and it worked just fine.

I HAVE also used the 2-for-1 fares, although rarely - I find the Y fares a deplorable value generally, unless it's truly last minute. The business fares can be quite a savings, however. Last year I used it for 2 tickets to Singapore in C, for a total of about 7400; that's 3700/each, cheaper than a Z fare at that time. Although not technically permitted, we were able to use systemwides to go up to F on the way back which was a nice way to end the trip.

For me, the value is in their service - they are knowledgeable UA agents and can do almost everything a normal UA agent can do except book wholly award itineraries (although they can see that inventory). They can issue upgrade awards, check for *A award availability, and will generally be more willing to work with you on complex itineraries. Since I run my own business, I value the services of a travel agency, and this is a good way to get it.

OTOH, even when I was working for a major corporation with travel agency accounts, the hotel/car rental prices I was quoted were always way more than I could get on my own. Ameniti provides little added value there, IME. I always book my own car/hotels online.