People either really LOVE SFX or they are not impressed. I am in the not impressed catagory. I was very impressed with SFX when I gave them my WM week (Labor Day week) at the Canadian in Vancover. They gave me all kinds of extras and I got a free diamond membership. Then, when it came time to give me an exchange I got offered garbage. I was looking for only Marriotts or Hyatts or Hiltons but I kept being offered non branded resorts. I was very hopeful at first but as time passed and I got no exchange I was first told SFX didn't get the inventory I wanted then more time passed and I was told what I gave up was too small. I got the impression SFX is the place to go for Manhattan Club, though.
I'm not an SFX hater, I just think they take care of certain members first, regardless of those members deposits and then everyone else gets what is left. In the end, I found an exchange on-line with SFX. I settled for only a studio but it is on Hilton Head Island for Easter week at a bed and breakfast. A full breakfast is included every day for a week and so is wine and beer at night. I happen to have a Marriott Surfwatch unit (obtained through II) for Easter week but we needed another room. At this point, I am skeptical II will find another week for me, so that is why I went with SFX.
I think if you want San Francisco, Manhattan Club, Mexico, and you are not afraid of unbranded resorts, SFX is a great trade company. I will admit, SFX provides personal service, just I am not at all impressed with their inventory. I do not think SFX gets many (if any) prime weeks at the prime branded resorts.
I've had the best success with RCI, but they cost the most in trade fees. II is second in my book and then SFX. Just depends what you have to give and what you want in return. I use II for my Marriott exchanges because there is just no getting around the power of Marriott preference in II. I can usually bank on getting a great week from RCI and SFX is probably a trade company I won't use any longer unless I want Manhattan Club.