Hi Louise
Honestly, my take on this is that people over-anylise a surprise trip. There are some important factors you need to weigh up, but really, you either like the idea of it or you don't. And if you do, the one aspect you do have to condsider is whether the kids will handle it. I can hardly see a child being told they are going to Disney (when they have been, love it and would love to go again) being upset about the trip.
What I would be very wary of is not to make up a story as to where you might be going. I had initially planned to tell DD if she asked, that we were going to see my friend in Spain. Six months later and the secret still safe, I changed my mind because (again, nature of the child) she would have built up expectations for her trip to Spain and then felt I had lied to her.
When I decided to do it there were a few things I knew I had to get straight in my mind and accept from the outset which included:
- I had to ask the obvious question: Does DD like surprises? (the answer in my case was yes)
- Will she miss out on the run up to the trip? (Yes, to a point, but she watches planning DVDs and youtube all the time and constantly talks about 'next time' so I could use this to incorporate into the planning)
- I had to accept that dropping a bombshell on anyone, especially a child may not have the desired reaction initially. I had to fight my thoughts so that I didnt build up my own idea of what the response should/would be from her side. I had to accept that she may be completely overwhelmed and become upset at first)
I also suppose it comes down to how much of the planning your kids do get involved in, and whether they sit for hours watching ride videos on youtube and the like.
This is very true. My DD's input in the planning in the past had been just that. It gave me a good idea of things that she wanted to try, which helped with the planning.
There was an 18 month gap between the previous trip and the surprise one. Kids (and their likes and dislikes) change rapidly when they are still so young. From this perspective, planning was a bit of a nightmare. I went on what she liked before when choosing character meals and putting together her autograph book. We ended up cancelling 2 ADRs because she just wasn't interested. It wasn't a big deal, but it did make it difficult.
For me the best part was the planning. I loved making things for her for the trip and every month I would buy or order a few things for a suprise pack for her. I enjoyed doing the autograph book for her. I loved keeping the secret.
The drawbacks, both practical and otherwise was as follows:
I missed it on some of the things I thought she would/would not like as her interests had changed
With the absence of a countdown, it never really registered that we were going until I was getting the things to the car to go to the airport hotel.
I was prepared for every possible reaction from DD except that she wouldn't believe me - at all. (It took about 10 minutes to convince her that I was serious

)
Packing was a nightmare and not having the cases out for a day or two beforehand definitely took away from the pre-departure atmosphere.
This last one, may not affect you, but it only came up when it was time to leave. I underestimated the effect of the build up followed by a fantastic trip and had a hard time coming home. I was a bit down for a good week afterwards and some of it was jet lag, but it has never been to this extent. (You will see how it already started on our last night when I get there in my TR) I am without a doubt that the intense anticipation for so long made for a very extreme withdrawal - like post Disney blues are not bad enough
I had to type this amidst countless 'emergencies' in the house so anything that doesn't make sense in this unchecked and unedited post, please feel free to question.
Last point I will add that was in my mind was that planning a surprise still leaves the option open to announce the trip at any point if you change your mind. If you announce the trip first, the surprise is out of the question
Hope some of this will be helpful
ETA: It might be a good idea to add that it was completely worth the effort for me and I am so glad I did it. DD still talks almost daily of the best surprise she ever had