tecreasey our control panel server is a VPS server, which is important because there's no recovery process available in Enhance currently for a disaster scenario where the control panel dies - so having a VPS that can be backed up with snapshots is critical. It's a 4c/8gb server, overkill for resources but it's being run commercially so the cost is negligible. If we were a smaller operation I would probably use a 2c/4gb VPS and not be worried about it at all. If I was just hosting for myself/hobby Id even consider going for a 1c/2gb.
Everything else is dedicated servers, because we run commercially and dedis get the best performance/price ratio. Although when we were testing using the DNS server roles we did setup Enhance on some cheap little 1c/1.5gb VPSs to operate as DNS servers, They ran perfectly fine with that small of cpu/ram, but during installation we did have to use SCREEN so the session could fully run (regular ssh connection will drop before installation can finish on tiny servers). Once the server is install with Enhance, then it runs great... We ended up not keeping the DNS servers though, since we do 100% Cloudflare on everything, didn't need the custom dns servers.
We run a dedi for our backups system just because we want to reduce any potential bottlenecks during a disaster scenario (don't want a VPS provider limiting our network transfer speeds, or IO, etc) - so it has 50cpu/128gb ram, 8TB NVMe storage, and a beefy network. I know a lot of people run their backup server on a VPS to reduce cost and simplify setup, and that's fine too, at least with a VPS it's easy/cheap to add additional storage drives or increase existing storage. There's some great VPS options that include high storage too, I'd be cool with using that kind of option if our needs were smaller.
You pretty much have to use whatever is best scaled to your needs. Enhance is really flexible in that you can put it on pretty much anything, easy to start out small if that's what you need and go bigger later. There's no per-server cost, so that helps, just have to find yourself some good infrastructure providers 🙂