We are currently with OVH and we have 3 dedicated boxes running out one of the french datacentres to cater for both our UK and EU players, We have been on dedicated boxes since our 3rd month after going live (12 days away from 4 years)
@Crapshot I used to work for Nitrado in 2015/2016 as there UK country manager, while these shared boxes are great for friends and more for some other games with Arma 3 once you start going past 20-30 players it requires more resources than these hosts actually offer as there is hundreds of VPS's per dedicated server and arma3server.exe is very resource hungry.
Our policy as always been 1 x 120 slot arma3server.exe instance per dedicated box to ensure maximum performance with our mission file.