I'm new to chickens as of May. I selected a mixed flock-- 13 chickens, 6 different breeds--because I don't know what I like yet, I wanted several different egg colors, and I'm curious about the different breeds. If you're happy with the golden comets and know that they are what you want, then I don't see any reason why you should feel pressured to get different breeds. Pretty sure that chickens don't care about variety. And having only one kind might make it easier if you want to raise/breed your own birds. I'm having lots of fun watching my various chicks of different breeds grow up, and while I'm pretty sure I don't want to hatch the eggs if we end up with a rooster (might make some weird mixes), they all get along great so far (knock on wood), and they were easily acquired from an online hatchery (Meyer's). I don't expect that they are show quality but they were fairly inexpensive (a few dollars each). Shipping was around $35, however. From my limited understanding, it's always a bit stressful to introduce new birds to an established flock, no matter the breed, because they have to establish a new pecking order, but I haven't had to try it yet. I'm looking forward to getting new chicks again someday, not so much looking forward to introducing them to the others.