I think most of the advantages listed as being attributed to a big or small school are actually about whether it is a good or bad school.
DC go to a 3 entry primary school.
I feel like the head knows most if not all the pupils and certainly will take a personal interest in a child. Both the head and deputy head will make the time to talk to a child or if a child needs to talk to them. Deputy head teacher and head teacher awards are highly sought over, the child gets to go and show off their work. Both the head and deputy head have the time for this.
The school secretary definitely knows all the children by name and I get through on the phone every time. (She actually recognising my voice,
The school still has a family nurturing feel. It also has a very inclusive feel. Kinda "We are big enough to take everyone and still be able to tackle what you throw at us".
Social fall out in small schools is horrific. There is too few children to spend some time with others or move to a different lunch table or all the other discreet ways DC's school have off dealing with such fall outs.
Small schools do not have the monopoly on space in playgrounds. Our big school playgrounds are fantastic. There's a big playground and a large field and also smaller playgrounds aswell, (some are for the younger years, some are just if you want a smaller space). There's very big scale play equipment. Some playtimes are staggered, some allow all the kids to mingle.
Some disavantages as I see them:
Drop on and parking around the school can be very Bad, (although from what I have seen this happens in all sizes of schools depending on location) It is ok if you drop off early (the playground is open significantly earlier then actual drop off times) and our school has multiple entrances that helps a little.
The sheer noise. Even with well behaved children the noise created by a whole year of children moving is significant. If you have a child sensitive to noise that can be a problem (although the children in DC's seem totally blasé that some children ear defenders, which imo says a lot for the ethos the school).
I'm not convinced by the supposed advantages of smaller schools.
I'm a big fan of the right school with the right leadership. I'm genuinely unconvinced size comes into it.