Shareholder -
I see no value in them. I occassionally call my corp.TA just to check the fares I am finding online and I usually am doing better and NEVER worse. Things like bonus miles or in SW's case, a 50% reduction in the amount of flights needed to earn a free roundtrip,for online booking,got me looking at websites. What kept me was the speed and convenience of booking online. TA's aren't open at midnight and they usually can't book award tix. Websites can. Add to this the savings and it becomes a very desireable way to book travel.
If I needed a package trip to China, I might use one but I would never book a package trip I always plan my own itineraries, even when going abroad.I hear they are typically good with cruises but I find it hard to believe they could do better than the internet.
I think they have great value for the in-frequent traveller but I question their value to the type of people in this forum.