I carry only the Lactina and my mothers have been very happy with it. I tell my mothers of preemies to use the Lactina at home and when they are at the hospital to use the Classic which is available to them free of charge. Not all NICU's may have this service but it helps and my moms are maintaining their milk supply. I had a mother w/ nipple confusion in an 11day old baby. Mom had been manual pumping and feeding by bottle since disch due to infant refusal.Sleepiness and jaundice were also in the history. In this area infants are still given sugar water to test suck/swallow and after feeds. Mom has large breasts & flat nipples which are inverted in the center. I showed her nipple rolling, Marmet technique and after working w/ the baby ( who fought the breast !!) she latched on and nursed x 45 min. What else will work on this type of nipple problem ? Does it eventually protrude completely? Thanks