yup most change the poi...and lose a fraction of power. but.. you set the gun up any way so its not worth worry about.
on a springer it can llengthen to an advantage of extra leverage. noise levals reduced but not much.
on a pcp..oooooo whisper quiet.
why the quiet? you get more shots in before everything runs off, you dont go deff... in a lot of cases you can even take several shots untill the target realises.
in rat turms, you get say 15 opertunaties unsilenced, verses all night silenced. long turm its a case of let the springer off once and they all hide, pcp wise that day i