**First:** both projects are awesome.

My personal point of view is that, using OpenVZ since 2013, it is a great, easier and more secure experience, including the new OpenVZ 7.

Through the history of documented vulnerabilities from OpenVZ and LXC:

 - From the [three vulnerabilities][1] found on OpenVZ, even when they were not fixed, they didn't allow privilege escalation
 - From the [eight vulnerabilities][2] found on LXC, one [documented on 2019][3] allowed code execution with root privileges on the host machine and other [allowed privilege escalation][4]

Some additional points:

 - The [venet][5] network model of OpenVZ is more secure and more isolated [ 1 ]
 - A container on `venet` network (OpenVZ) cannot sniff the network traffic of neighboring containers [ 1 ]

[ 1 ] https://wiki.openvz.org/Differences_between_venet_and_veth


As stated in [this article][6]:

> OpenVZ does security via the "bottom up, all included principle".
> Containers are very solidly isolated against each others. Over the
> years there have been a few issues and vulnerabilities, but in general
> you can say that they did a splendid job. Because security was first
> and foremost on their mind. Not just the container isolation, but also
> network security. If you allow root access to an untrusted client on
> one Container, then you don't want him sniffing the network traffic of
> neighboring Containers, the node or even the whole subnet. For that
> reason OpenVZ had introduces the "venet" network interfaces, which
> tackled that in a really neat, orderly and (for the end user) very
> simple fashion.


  [1]: https://www.cvedetails.com/vulnerability-list/vendor_id-12951/Openvz.html
  [2]: https://www.cvedetails.com/product/27105/Linuxcontainers-LXC.html?vendor_id=13134
  [3]: https://www.cvedetails.com/vulnerability-list/vendor_id-13134/product_id-27105/year-2019/Linuxcontainers-LXC.html
  [4]: https://www.cvedetails.com/vulnerability-list/vendor_id-13134/product_id-27105/year-2014/Linuxcontainers-LXC.html
  [5]: https://wiki.openvz.org/Differences_between_venet_and_veth
  [6]: https://www.aventurin.net/index.php?mact=News,cntnt01,detail,0&cntnt01articleid=28&cntnt01detailtemplate=Simplex%20News%20Detail&cntnt01category_id=1&cntnt01returnid=1