Interestingly enough, under our Breeds section Red Sex Links have received a 93% positive review rating from among 54 BYC members (https://www.backyardchickens.com/products/red-sex-link), which is exactly the same positive review percentage rating (also 93%) as Rhode Island Reds, a heritage breed (https://www.backyardchickens.com/products/rhode-island). These numbers would seem to suggest that those who've had major health issues with their Red Sex Links are the exception rather than the rule. My advice to gottaloveanimals is to read through these reviews before purchasing Red Sex Links and then make the decision whether to purchase them or not.
Maybe it's not surprising then that I love both my RIR's and my red sex links, lol. Other people have had negative feelings about both. On the other hand, I might be the only person around that had trouble with Black Australorps behaving badly, lol.
@gottaloveanimal there are going to be mixed opinions on everything...breeds, coop designs, hatcheries, etc. You just have to go with what works best for you.