My little girl was using NOK from birth, I tried avent but for some reason she didnt like it.

These days she still uses a dummy at sleep time. She's not so fussy now, she uses NUK, MAM, Tommee tippee & one I bought from babies galore (not sure of the brand) but she liked the look of it & it's pretty nifty as it has a cover that opens so baby can suck it (when its opened its the shape of a normal dummy around the baby/childs mouth) then when its taken out the cover closes keeping the part thats sucked covered.... we love it haha

I think its just a case of trial & error until you can find the one your baby likes as every baby is different....

Good luck