My son is 2.5 and he has been potty trained for 5 months.  I am pregnant and too lazy to wing it and see how he does during nap or bedtime without a diaper so I use a pull up or a walmart brand cheap diaper and if he wakes up dry, I use it for the next sleep time.  I know nothing about cloth diapers and really didn't want to invest in them for this purpose.  This swim diaper worked perfectly! Its easy to wash (another thing i was concerned about cloth diapers, you have to have special instructions and buy special detergent), you just put it on cold and air dry.  Unfortunately (or fortunately!) my son has been using this for a week and hasn't peed in it yet so I don't actually know how absorbent it is.  I'm also planning on using this as a swim diaper as well, just in case he poops. My son is small compared to other kids his age, always true to size. I ordered the 3t because everyone said it runs small and i was glad i did.  i still feel like its a litle tight for bedtime, he has mentioned it but not really complained and its comfortable for him to sleep in, i was afraid it would be too loud being waterproof and its not.  i ordered another one and got a 4t so it would be a litle bigger and even more comfortable, probably use that one for sleeping and not try it for swimming though since im sure the legs are a little bigger.