Hi Daniel,
There’s a “technical” and “practical” aspect to this question 
Let’s start with the technical part…a lot of networking people will tell you that you shouldn’t have > 200 hosts in a subnet since there will be too much broadcast traffic and it will slow down your network. This might be true 10 years ago but nowadays, your computers won’t be bothered much with broadcast traffic and it shouldn’t be an issue for your switches. You could probably put ~1000 hosts in a single subnet and not notice any performance issues.
The more important issue (the practical aspect) is that a single subnet/VLAN is one failure domain. Let’s say we put 1000 hosts in a single subnet and one computer has a broken NIC, sending non-stop garbage broadcast frames. This will affect the entire VLAN and your 999 remaining hosts.
By breaking down this big VLAN into four smaller VLANs, a broken NIC would only affect one VLAN…not the other three.
So for practical reasons I think it’s best to stick with /24 subnets. They are easy to work with and you’ll have multiple failure domains.
Rene