I went to one....but it was a long time ago! I loved it. Everyone I know who went to it loved it. Everyone did very well afterwards - but as I said, it was said it was a long time ago.
Have you asked the school (the one you are considering) which secondary schools pupils tend to move on to? Should give you an idea. Other than that, if you love it and it feels right to you, if the children there seem excited by and keen to talk about their work, and confident - then I'd be very tempted, myself