The choice between KVM VPS and OpenVZ VPS depends on your specific needs and requirements. Here are some factors to consider when comparing the two:

1. Isolation: KVM VPS offers full virtualization, with each virtual machine having a separate kernel and operating system. This provides better isolation between virtual machines, ensuring that any problems or changes in one virtual machine do not affect other virtual machines. On the other hand, OpenVZ VPS shares the host kernel, which can lead to less isolation between containers.

2. Flexibility: KVM VPS allows you to run different operating systems and customize your environment to suit your needs. It offers greater flexibility in the choice and configuration of operating systems. On the other hand, OpenVZ VPS restricts you to the same kernel as the host and only runs compatible operating systems.

3. Performance: KVM VPS tends to offer better performance as it provides dedicated resources for virtual machines, including CPU, memory and storage. Since OpenVZ VPS shares resources between containers, performance can suffer if other containers on the same host consume too many resources.

4. Resource management: KVM VPS allows for more precise resource allocation and management as each virtual machine has dedicated resources. OpenVZ VPS, being container-based, can be more efficient in terms of resource usage as it shares host resources between containers.

5. Security: KVM VPS, with its separate kernel and operating system, can provide greater security by isolating each virtual machine. OpenVZ VPS, with its shared kernel, may have some security concerns as a vulnerability in the kernel can affect all containers.

Ultimately, the best choice depends on your specific use case. If you need strong isolation, flexibility and the ability to run different operating systems, KVM VPS may be the preferred choice. If resource efficiency and performance are more important, and you can work within the constraints of a shared core, an OpenVZ VPS may be a suitable option.