Austin pretty much nailed it, Silicone nipples are sturdier but they're a lot stiffer, the Littleforbig big shields are way nicer than nuk 5's but they don't have a vent on them to make it reinflate, they're not very hard to tear apart, all you really have to do is taking a sewing needle heat it up with a lighter and poke a hole towards the base of the "button" that the nipple sits on, after doing this modification to it it's honestly my favorite paci ever :3