I have 6 and will hopefully have another 1 or 2. I had twins first and all singletons since, not opposed to having twins again though.
Everything is pretty hectic, you just have to accept that everything will not go according to plan.
My oldest 2 are 9 now and a huge help. I was one of 4 and there was quite a big gap between me and my younger 2 siblings, i remember having to do an awful lot for them. It wasnt that i didnt enjoy it, it is just not want for my children. I am lucky in that one of the twins in particular loves babies, he often asks to look after the youngest. It does help enourmously, if i want a shower in the morning, go for a wee alone >
I have always wanted lots, maybe 5. I just remarried after being with my first partner for 9 years. My husband has taken on all the children and is fantastic. My ex is predictably a twonk. Cant really fault his fathering per se though so all the others do go and stay with him. This leaves little Beau (latest baby, first for my husband) alone. Only fair he has some playmates for all year round, i cant imagine him having to do Xmas alone I take it in turns with exp and his girlfriend > she is at least 24 now, more child like really than them He is 38. (you know what happened there dontcha?)
Anyway, i love having a big family, the only thing i moan about is the washing, well that and the 2 year old who is like a destruction machine at the moment
Good luck!