That's the basic idea, although I wouldn't suggest the hardware I'm running is particularly high powered (or even new for that matter, 7+ years old).
I have learned that more memory is an asset as well - again within limits.
512MB is tight in some scenarios (I still have one box with 384MB! ), 1GB is good, 2GB is great, 3GB+ is fantabulous.
The packages caveats always apply, asking the box to do more than route and basic firewall and/or VPN adds to the required resources.
When you get to the Snort/Suricata, Clamv, setups a whole different set of parameters get invoked that are best described in their respective forums.