Not hard to tell how effective DA/SA is. Just look at all the top pistol competitors and special forces units who choose it!
(Can you say ZERO?)
can you say "uninformed"?
the M11(sig sauer P226) pistol is DA/SA
the M9(Beretta 92FS) is DA/SA
special forces, recon, mobile expeditionary and mobile comms all use these and use them often.