Which QNAP mode?
I'm using a TS-251D
The TS-251D has a PCIe slot, where I added a m2 ssd. Here I put kodi, cups, OMV and for all other apps I'm using docker.
Therefor the added ssd is also helpful, it's hosting also the volumes for my docker container.
The 2 bays are only for data.
Also I replaced the 2 G memory. It's too small. I'm running now 8 G.
I'm happy with that. The TS-251D, for me is like a standard intel PC, but smaller, nicely designed and cheaper.