I worked as a teacher in one of their schools.
They didn't look much different from other kids, apart from girls having long hair and wearing large bows. The boys had very groomed hair too. Their uniform was very standard, and the same at all their schools worldwide.
I found the boys to be really naughty, but the girls were lovely.
The mums were lovely and very happy to chat (they drove the minibuses so you spent a lot of time with them on trips).
They didn't eat with us, but made lots of delicious food for us. The men were pleasant but more distant.
I think if you saw one Brethren family, you wouldn't particularly notice, but when there's a group of them you can really tell.
I wouldn't say the women or girls wore long skirts, but there was a certain 'uniform' about them.
They look after each other with their various family business and obviously do well. I imaging interacting with them will be very pleasant .
As far as meeting houses are concerned, there might be maybe six families that attend one MH, so very small. The men will take in turn to preach and the women announce the hymn numbers. They go everyday - several hours on Sundays, and then in the early evening.
At school, gossip got round the families very quickly as the families saw each other every day. I had to be on my toes not to teach anything that could be offensive!
They are not like the Amish. They want their children to be educated by professional teachers to beyond L3, especially in business/accounting.
They love technology - especially computers (but they have the same filters at home as they do at school). They don't have live feeds of current news - no TV, radio or newspapers, but that doesn't mean they are ill-informed.