Hello cozzie.
My son went to the Falcons Pre-Prep and spent one year at the Falcons Prep. I cannot recommend it highly enough. The pre-prep is very established and its reputation for being a fantastic school is well known (proven by happy parents and amazing exit results at 7+ for those who choose to leave).
The prep had a couple years which were hiccups, nothing to do with the teaching or the school which have always remained very, very good, but due to 1) a new school starting up in the Richmond area which offered steep tuition discounts to lure parents away and 2) last year's year 4 some parents panicking that the school does not specifically prepare for 11+. However, if these parents had just waited for the 11+ results to be sent out, they would have seen that there were acceptances to Tiffin, Latymer Upper, Colet Court, City Boys, Kings, Kingston Grammar, etc.
Now, specifically regarding the school: it is a very friendly school with a wide range of academic ability which are all well taken care of. My son only spent one year there as he took the 8+ and moved on to Colet Court (the school has excellent results at 8+ with between 75-100% acceptance rates to Colet, Westminster and Kings College). The year group was split into 2 classes and divided informally into tables within the class. All tables were well catered for with the top table (all boys which took the 8+ and all were successful to their 1st choices). When my son arrived at Colet, he seamlessly fit into the top third, demonstrating that he was pushed at an adequate level. Those at the bottom and middle are also well taken care of.
Teachers are all enthusiastic and genuinely caring, and specialist teachers teach subjects from year 3. Latin is taught from year 4. Loads of sports, and the fact that the school abuts Old Deer Park and its facilities is a great resource. Great range of extracurriculars, and built in time to get homework done at school is also good. Needless to say due to it being recently built, fantastic facilities and a very good canteen.
The only negative about the school is the homework level - it is not a burden (less than half an hour a day at year 3-4), but compared to other preps, it is at the higher end. I suppose it is because they want to do the maximum possible to get the boys ready for the top London day schools, which have gotten increasingly competitive to get into.
Another wonderful thing about the school is the parent group - a very laid-back and friendly group. Loads of social events, and very welcoming to new parents.
I highly recommend the school to anyone.