Once again I see chat on the on line groups about this or that yarn and people making assumptions, not really understanding their yarns, what the numbers mean, how different qualities of yarn come about, WHY they come about, perhaps.
Having come into weaving via the orifice of a spinning wheel, I arrived with a basic (*very* basic) understanding of fibres, twist, how different methods of spinning will produce very different results, even given the exact same fibre.
Spinning is the same as weaving insofar as everything is on a spectrum, from one extreme to the other.
How those extremes affect your cloth will depend. (Bet you're surprised at that....)
So, back to my black and white photo of Brassard ring spun 2/8 cotton (top) and basic American quality open end spun 8/2 cotton (bottom).
While they both will have approximately the same number of yards per pound, it is quite obvious that they are not identical.
The Brassard cotton is denser, smoother, more tightly twisted, stronger, less absorbent while the American quality of 8/2 is less dense (will shed more fibre), weaker, more textured, less tightly plyed, more absorbent.
One is not 'bad', the other 'good'. One will be better than the other in certain circumstances.
New weavers rely on more experienced weavers to guide them. But at some point every weaver needs to pay attention themselves. Use critical thinking, analyze your results. Come to your own conclusions.
Always admit that you don't know everything there is to know about the construction of cloth. Always be excited about how much more there is to know, to learn. Learn from 'mistakes'. Results are just results. It is what we learn from them that matter.
Happy weaving - and learning!