For gateways, it really depends on what assets you're protecting, where they are hosted, and the performance requirements as to whether you should use a VM, Open Server (Hardware), or a Check Point appliance.
In general, Open Server gateways (also applies to VMs):
- Must be licensed for the number of processor cores you want to use
- For Open Server hardware, we only guarantee support for three years
- Have a higher support cost
Also, some features are only supported on Check Point appliances (e.g. Hyperflow in R81.20, Dynamic Balancing in R81+).