To use their search feature, you have to sign up for their mailing list. I just gave one of my junk email addresses the first time I used it.
I use them for searching and then typically check the cruiseline's website and call CruCon.com to see if either of them can give me a similar or better deal. I've booked with VacationsToGo twice (sailing with cruiselines CruCon doesn't work with) and both times I've had customer service issues.* I've never had issues with CruCon or booking directly with the cruiselines.
*The first time, the guy who was supposed to handle our booking went out sick for a week, and by the time he came back, the cabin class we wanted was sold out, so we had to pay more. (It would have been nice if the booking had been transferred to someone else to be completed in the meantime.) Then there was a screw-up with our dinner seating but the maitre d' was able to fix it on board with a bit of patience and a few nights bouncing between tables. The other was on my Antarctica trip and kept me from getting to camp overnight on the continent. They gave me completely wrong information, and when I talked to them later, they said, "Oh, well that's how it works with other trips from that company." Barely even an apology, and I missed out on a potentially once-in-a-lifetime chance. Yes, I'm bitter.