I watch a friends daughter, and she has gotten sick from my kids, and my kids have gotten sick from her daughter, but I don't happen to care if she is here, sick or not. Most of the times, my kids, and her daughter have already shared the germs, and are sick at the same time (the last stomach bug, my daughter, and her daughter woke up in the middle of the night within a half hour of each other throwing up). So, for my friend, she has missed MUCH less work, because I let her daughter come sick, where as in a daycare, they will not. Plus, kids in there first year or two of daycare are CONSTANTLY sick, it is the nature of the beast. I treat her daughter no different than mine, we are always out doing things, parks, zoos, we have gone pumpkin, and apple picking, movies, indoor playplaces, a small amusement park, library story time, ballet class, her speech teacher came to our house, and my friend pays a fraction of the cost. I think, it is up to who you find, and what you are comfy with. Next year, I will have my daughter in kindy, one in prek 3 days, another one in another preschool progam 3 days, my friends daughter in preschool three days, and two newborns (she is due anyday, I am due in august). I also worked in a center for a few years. I think, it is what best fits your schedule, what you are comfy with, if you trust the person, if you trust the center, how many sick days can you take, will a inhome take them sick, millions of variables.
I would write a list of both that way you can keep track of pros and cons. Good luck, and the best advice is go with your gut, and see how happy your kids seems there, that is the best way to tell!
Good luck!