My friend just went to go on a semi-guided hunt, and ended up seeing the set-up and driving back home...
I have looked into such experiences as well, as time is precious, and with limited time, scouting and finding birds would likely take longer than the allotted time I would have to take off.
Generally, with a guided hunt, you have a guide that takes you to a spot, and does all the calling, and you shoot a bird. Some guides are not afraid to move to a bird, and some guided hunts you are stuck in a blind with the guide.
My understanding from inquiries thus far is that a semi-guided hunt generally means being put into a blind (hopefully where there is some bird activity). They generally do not want you moving from the blind to hunt a bird. (This makes sense, as they do not want clients hunting too aggressively and pushing birds out, or encroaching on another hunter's experience).
I have other friends that have payed a trespass fee to hunt specific properties known to have birds. It is up to them to find the birds, but they can move around the property freely for the time they have the property.
Were it me, I would try to find an outfitter with a good reputation, and do a semi-guided hunt, in which I had some freedom to move around... If that is not possible, I would try to find an outfitter in which the guide has no issue NOT calling (as that is a large part of the enjoyment for me), and has no problem moving on birds.