We got married near Costanoa and had our guests stay at Costanoa for the weekend and had our farewell brunch there as well. We planned to have the welcome dinner (for all of our guests there also) but Costanoa canceled the space about one month before the wedding. We found that working with Costanoa was the most stressful and challenging part of planning our wedding. I have pasted excerpts of the letter we wrote to the GM before the wedding. Although we told Costanoa of our disappointment before the wedding, they made a major blunder the weekend of the wedding. Other complaints are below. It is a beautiful spot but I am so glad that we didn't have the actual wedding there. There special event staff are terrible to work with.
Our specific complaints were:

1) We went to check on the brunch about 1 hour before it was to start and the staff had thought that they were closing the space one hour before our brunch was scheduled to end. Costanoa knew the timing as they had printed our schedule and brunch tickets for the guests but the reservations/ special event staff never told the cook/ server. They also ran out of 1 of the 2 dishes about halfway through the brunch even though we had way fewer people attend then we expected.
2) When we were negotiating our agreement with Costanoa, we were clear that we planned to use Costanoa's outdoor spaces for our welcome dinner and farewell brunch, but that we did not plan to hire Costanoa's catering for food and drink. At the time we made the agreement and reserved the space for our welcome dinner, Costanoa did not raise any objections. In fact, we had our agreement altered to state that we would only be required to utilize Costanoa's catering if we reserved its indoor spaces, and Costanoa signed the agreement with this alteration. In addition, we have an email record to Costanoa saying specifically that we would be reserving the Cascade Lawn for the welcome dinner but would not be using Costanoa catering. We included the location of the welcome dinner (the Cascade Lawn) in our invitations. Then, after our invitations had been sent out, we were informed by Teri, your sales manager, that we weren't allowed to use the Cascade Lawn without also hiring Costanoa's catering service. She offered to let us use the Rossi Road area as an alternative, but this area is not nearly as attractive as the Cascade lawn (it is a small grassy area on the road). We moved our welcome dinner to an alternative venue that would be more accommodating.

3) While I was discussing the welcome dinner arrangements with Teri, she told me that she wasn't going to be able to sell a wedding that weekend because our guests were taking so many rooms. When she said this, it was as though she did not appreciate the business we were bringing to the hotel because we weren't contributing enough to her sales commission.

4) The most frustrating part was micromanaging the reservations. Costanoa made repeated mistakes with our guests' reservations. Some guests' reservations were lost, and they needed to make new reservations. Some guests were not included in our wedding block and were not given the block discount until we double checked the list. Some guests were not given the weekday rate for their Thursday night stays. Many guests told us they left messages to reserve rooms and did not hear back from Costanoa for a significant amount of time (weeks) or never received a return call. We were not expecting that we would have needed to double check Costanoa's reservations, given that this is part of your business, and we were aggravated that we needed to spend so much time on this. We literally had to check every reservation.

7) In general, we were disappointed with the general lack of responsiveness from Costanoa. Throughout the process, we sent emails with questions that were not returned sometimes for weeks or until we resent the emails several times. There were several other examples of how the planning process with Costanoa was complex and tedious because of the need to continue to check and double-check their work. We would much rather have been able to enjoy the weekend rather than worry about whether we can trust Costanoa's work.