A bit of an open question.
Like anything else quality usually costs more than run of the mill. The two biggest quality issues to worry about is moisture in the filament (indicated by popping noises when printing) And consistent filament size. Te issue here is this the amount of filament delivered by the nozzle. not critical for infill but on outer layers you can have a thin spot or have hanging loops if the filament is suddenly large and you are printing a bit of overhang. The other issue is unwanted contaminants in the material that will cause a nozzle clog.
Most folks use straight ABS or pla to start out.
Many manufacturers are adding powder to the filament. wood powder ,metal powder, carbon fiber etc. Here you may need a larger and or harder nozzle as some material will easily clog a small (0.3 0.4 nozzle and carbon fiber and steel powders will wear a brass nozzle.)
Advanced users may use Nylon or PET or even elastomers for a rubber effect. These materials require quality all metal hot ends , and higher temps . the benefit is stronger parts that can be used for real world applications.
IIRC octave filament is made in USA
http://www.octave.com/
Precision 3d is another one made in usa and these guys have many years experience extruding plastics.
http://precision3dfilament.com/
Anonother great company is
http://printedsolid.com/
The owner is an engineer and has likely tested everything he sells. He sell only quality printers and material he knows works.
Based in Delaware USA.
Like anything else buy a good name brand from a known factory and it will likely be good if you get a bad roll they will likely make good on it. Buy from an unknown manufacturer in asia and you will save money but it is a gamble may be good may be a waste of money.
And yes the material manufacturers are continually looking for ways to improve existing products and develop new ones.
Tin
Disclaimer I have not tried octave filament or precision 3D . I have spent time with the owner of printedSolid. I have no vested interest in the company other than trying to help a USA businessman.
Soliddoodle 4 stock w glass bed------Folger Tech Prusa 2020 upgraded to and titan /aero extruder mirror bed
FT5 with titan/ E3D Aero------MP mini select w glass bed
MP Utimate maker pro-W bondtech extruder
Marlin/Repetier Host/ Slic3r and Cura