Yes, very fun! They're doing really well, it will be interesting to see what they look like as adults. Since the hens are hybrids the chicks will not be the same as their parents.
In Sweden, organic and KRAV (KRAV farms have to follow special rules for the well being of the hens) have roosters among them, this is why it's possible that some eggs are fertilized.
That is cool. *Peep* *Peep*