Be aware that there seems to be a bug limiting the performance of the P2000 right now. HW transcoding isn’t working on pms version 1.15.1.710
It’s unclear if Plex or the Quadro driver is to blame, but the Geforce is reported performing great without exhibiting the problem. The nvenc and nvdec hardware on the newer 2080 chip is also producing higher quality transcoded video.
My advice right now would be to save the money and try the driver patch to unlock the performance of the card you already have. https://github.com/keylase/nvidia-patch/tree/master/win
You probably have to disable the driver integrity checks in windows to do this, as editing the driver removes it’s digital signature. https://www.maketecheasier.com/install-unsigned-drivers-windows10/