The FSS is anything but a perfectly acceptable tool, there are numerous flaws with the overall implementation. The optional module would help mitigate the issues and address other concerns but the FSS was essentially rushed out the door before it should have been.
I don't know, in terms of a tool in a game to find things it's Ok. Obviously I personally don't like it, got bored using it very quickly, but when I say it's acceptable, it's because as far as the game goes it solves some issues that potentially stand in the way of exploration gameplay. Notably, it removes the need to fly potentially huge distances just to scan a body, and additionally it notifies players if there's something on a body so that they can then decide if it's worth flying out to.
Other than a few bugs, which I have not found particularly irksome, and I play in VR, I'm not sure what the flaws are. The fact that it takes us out of our cockpits? I noticed and pointed that out as a potential issue after the first reveal, but I don't think it's a flaw, I suspect it's a design / technical limitation. Just as with the galaxy and system maps, we are no longer controlling our ships, so it has to be out of the cockpit, and I don't see that changing any more than I see the galaxy and system maps becoming cockpit overlays.
Otherwise, it works fine for what it is, a mechanism that is at least hands on, active rather than purely passive, much quicker for scanning than the previous system, IMO very easy to learn and use. Oh, and for 'traditional' exploration, finding (and scanning) ELW's and the like, much more efficient than the previous method.
As I said, whether we like it or not is a different matter, and subjective. Personally I gave it a decent shot, went for three exploration trips after it went live, but simply didn't find it compelling enough gameplay to keep me going.