There are several difficulties with CIG and some positives.
Using the title 'Grammar' in Bucks with its selective state system is very misleading and that alone would make many suspicious. For a school to change its name so quickly after foundation is also unusual. Its financial situation has been chequered - its first iteration went bankrupt.
Equally, comparing other IB schools to this one which hasn't yet completed the fully certified course with any of its students, cannot give a true picture of the quality of its teaching. It has no track record. There is a long-standing IB course offered at the ACS Hillingdon school which achieves very good results and has done for many years.
Whatever is said about the location, the reality is that it's an adopted site from the old Bucks New Uni. Staff have to keep a close watch on students because it isn't secure. The old accommodation blocks on the edge of the site are rented out, Newland Hall itself is used as a wedding venue and the rest of the park can be rented for conferences.
That said, children who don't fit the local grammar mould can be very happy here. From what I have been told, it is not one for high-flyers, but quirky children have space and time to develop in a different way to the linear NC. Being outside the NC also makes it more accessible for children with SEN.
Go into this school with your eyes open. It isn't necessarily what it claims to be, but equally it can work for children who need something outside the typical Bucks experience.