I tried them two years ago and had a similar experience. I gave them my 200K+ balances with 4 different airlines and asked for any 2 week period over the entire summmer. I got a message back that basically said "Sorry, nothing available on United with your US miles." I asked about the others and got an "Oh, yeah, we can check those too", followed by "sorry, nothing there either" and that was the end of the effort for my $$$.

I've heard stories about them working several days on creative alternatives, using "tricks of the trade", etc. - both of my responses came within a day, so I'm not sure anything other than checking the CRS was done. I suppose I wasn't out too much $$$, but it was the last time.

I've heard others that have had much more success.