Yep there are quite a few of us CRGS parents around, so ask away.
Have no knowledge of the other school you mentioned but maybe part of the reason there is little 'discussion' about CRGS is because there isn't much negative input
It certainly isn't somewhere for a lazy child to coast through but apart from that it will suit most who get the score needed for a place. If DS has been coached beyond his real ability then he might have a tough time keeping up but the vast majority of the boys cope just fine and are given the appropriate support and encouragement.
Masses of extra-curricular activities and new ideas also encouraged.
Ethos is really special - great relationship of mutual respect between staff and pupils, especially as the older boys mature.