My experience has been good. DD settled more quickly than DS did at Pate's, but that might be more a gender thing. It seems that they receive less homework than other grammars, but that is only hearsay, I don't have personal experience to share. Both DCs very happy, love the house system and competitions. The only issue we had early on with DD was sorted as soon as we spoke to her tutor. Have found it to be a very supportive and friendly school and the students generate a good atmosphere. Good interaction between senior students and new students, especially in house music - and best of all house drama!
Yes, it is an outstanding school academically, but Pate's is more than just grades. Take your DC back for another visit if possible, as they often can tell intuitively if it is the right school for them. Also, take into account travel and ease of travel and ability to join in after school activities (if not bus dependent).
Also, do you want them to be in a mixed or single sex environment? Something else to consider.
All the best in your discerning process