Nvidia graphics card - nouveau or the proprietary driver?

[Naron]

I have an older system which has a Nvidia GT 640 card and I want to install Debian 10 on it. I'm in doubt on what driver to choose for the GPU: nouveau vs binary Nvidia.

I would like to have some performance out of this card (I know, it's quite old but good enough for me) and I understand that the binary driver is the most capable in this regard but personally, I like open-source drivers better, simply because they have longer support and security patches (binary drivers are maintained by the manufacturers and they can end the support at any time, I don't like this).

So, simply put, I have to choose between performance vs security and support. Some advice?

[LE_746F6D617A7A69]

GF640 is a Kepler card, codename NVE0, and the Nouveau support for this card is nearly perfect, see this:
https://nouveau.freedesktop.org/wiki/FeatureMatrix/

I have GF750 (same family) and with re-clocking enabled, the Nouveau easily outperforms nVidia binary drivers, in all aspects:
http://forums.debian.net/viewtopic.php?f=16&t=146141

So, If You don't afraid to tweak Your system, I would recommend to use open-source driver