I said three, because I am fine with a three year old ffing, but my 3.5 year old is rfing, only because she likes it better and still is with in the proper weight and height of her seat to do so.
That said if a situation arises where it is very inconvenient, for her to rf, I turn her till the situation passes now.
Like this week coming up, I will be visiting family in NH, I am going to have her ffing while there because I will need to carry my sister mom and dad in the minivan, which has captians chairs in the second row, and then the third row is the typical bench seat, I had two rfing seats, a my ride, and a marathon, in the second row, but how are my sister and dad and mom supposed to get to the third row, they cant crawl under the rfing seat like my 7 year old does, so one of the seats will turn around for her for the week, no biggie, she is old enough, its not too huge of a deal now.