Good question Hatwoman. DD2 starts full-time school in September and Jura and I have been discussing this issue on another thread somewhere. Thinking about this strategically (Anchovy is the master of this), you need to work out all the tasks required to keep the household afloat:
1 School runs
2 After school childcare
3 Help with homework
4 Food shopping
5 Cooking tea for the DCs
6 Cooking an evening meal for you (could be combined with 5)
7 Errands (e.g. buying birthday presents for parties)
8 Laundry
9 Ironing
10 Cleaning
Currently our full-time, live-in nanny does 1 - 7 and a little bit of 8 and our cleaner does 8 - 10. I think it's virtually impossible to find a single person who is willing and able to do them all (other than an SAHM!). Somebody who can help with the homework may well be unwilling to do your cleaning and vice versa. So, I know that our nanny (NZ teacher) really enjoys the childcare element, particularly the homework, but struggles with the cooking. Our Czech cleaner is fabulous, but really couldn't manage the homework and whilst she would love to look after the children probably wouldn't be disciplined enough with them.
I think that our nanny will be ready to return to full-time teaching in September, but even if she's not, I don't think we can afford to keep her on, particularly as there is no way she would do 8-10 (fair enough!). She's talked about combining teaching and childcare, but deep down I realise that just won't work - too many competing interests and needs. We've got plenty of space, so currently we're thinking of getting an au pair couple who will do everything but the homework and hiring a maturish student or teacher to do the homework for one hour a day (DH or I are back at 6pm but it's too late to do homework). We may also get a student/holidaying teacher to do a chunk of the summer holidays whilst our au-pair couple take a break back home. That's the current thinking....
Mrs Wobble's sage advice on the other thread was, if it's working now, enjoy it and only start worrying about it nearer the time!