Your informations what is better IMHO are outdated. Right now steam vr beta is improved with correct SS slider ( and tex. filtering). Steam Vr beta SS 2.0 is equally to HMD Q 2.0 now. You dont need any external app like adv. open vr controlled over htc controlers or chaperonswitcher controlled via mouse. First one may take some resources from your machine becouse of compositor.
To clarify, I wasn't talking about HMD quality slider, I was talking about Elite Supersampling which still seems to suck... a lollipop.
Also, whether its via steamvr, ovr or via editing json files, you still set one parameter in steamvr, namely RenderTargetMultiplier. As for values its up to individual to decide which are best for them and their graphics card. 2.0 is very high and I imagine it will be quite taxing on the machine, and you wouldn't notice the "draw" from OVR dashboard (which is a C++ app) at all. Probably having a browser open in the background will cost you more than ov
Regarding uses and features of Openvr, there are many more beyond simple render target override. For example it keeps track of how much you turned which is immensely helpful if you have the dreaded new thin cable like me. It tends to get tangled and to untangle it I simply rotate as many times in the right direction as OVR shows

. I also use it for easily, in VR switching of chaperone profiles which I set via
ChaperoneTweak. In tweak you adjust the chaperone in VR and can easily add corners to walls, pull them and whatnot. Then save it to ovr and you can easily switch between standing and roomscale, chaperone displayed and not etc. etc. You also get the access to async options in one place instead of scattered through menus. Speaking of which, I prefer to adjust things from the headset instead of taking it off, moving to where I put mouse and keyboard, adjusting, putting the headset back on... you get the idea. Of course YMMV.