almost any one part can be set up a number of ways, and the results will be different with each one. One person might think a duopar is perfectly awesome shifting a 6 sp freewheel with a bar end made by shimano, and another person might set it up on a 8 sp cassette shifted by a dt lever and to them it sucks.

In other words, not only is everyone application and setup different, so are there needs and experience. There are WAYYY too many variables to really get a right answer to much of this stuff. It will always be that way.

So the best thing you can do it just try parts and bikes and systems and see what doesnt and does work for you and for the most part, forget about everything else.

And disregard almost all general statements about brands.