actually, Kalle - dithering is for the bit rate, not the sample rate. dithering should be the last thing you do before export and is only needed if you're going from 24bit or higher to 16bit export.
if you are recording at 24bit (which you should be if possible) then when you export, you use dither to add noise in the empty bits when reducing from 24 to 16 (16bits is needed for wave files and mp3 exports so that CD players will play them).
I know it sounds counter-intuitive to add noise to your export, but that's what it's for. as far as which algorithm to use during export - I can't really hear any difference in any of them.
as for Alicecarol aka "spammer scum" - you've been reported.