Adjustable triggers and fancy firearms are really great, if one has two valid skill sets.
1.) Obviously is the ability to employ said weapon properly as mentioned in OBG's post regarding M1A knock-offs. (BTW Good shootin')

2.) One must be skilled at adjusting said trigger mechanisms. (Or employ a competent gunsmith) I have personally witnessed several PPC and IPSC competitors end up with a full-auto 1911 government model due to unskilled hands tinkering with John Brownings finest creation.

My favorite butt whipping I ever received was during run-ups for the junior olympics in trap and skeet. I stood on the line with my finely tuned 1968 model Winchester 101 ready to do battle with the best in the state. Along walks up a young man with a Savage single shot 12Ga. In my mind I laughed and thought it was time for someone to learn from his betters. Someone did. I still think my father has the picture of that young man, his Savage single 12 and the trophy my snotty nose thought was mine.

Don't get me wrong, Every firearm I have except the Glock's have the finest triggers (and everything else) I could afford, but there is a reason for the word RIFLEMAN. The man is in control of the rifle and their destiny.