My DD's have been in cc from ~ 9 months of age. I preferred that as I had some experiences with private Nannies that worried me a little BUT that is definitely a personal preference! I think the key to whatever you choose is to go with your gut feel and how the options align with your needs/expectations.
Thing such as settling routines, nappy choices (some centres etc don't do cloth here) and parenting philosophies etc. Also for us opening hours etc were important as we have to work over Christmas and often have early starts, awfully practical but important as we have little/no back up.
I like that our centre has a mildly chaotic feel and that there always seem to be a few things on the go when I go to get the girls. They have also been very flexible/creative about helping my DD1 deal with her separation anxiety at drop off as well.
It is a hard one as I was hoping to get FDC before the kids hit kinder age and then swap them over but we have ended up having a day at cc and then enroling in our local council kinder as well - in hindsight it has worked well so far but there have been plenty of moments that I felt awful amongst it all!!!
Hmm not much help am I???!!!!