we've had au pairs in the past - 1 was brilliant, 1 decent, 1 pretty poor. All 3 had prior au pair experience and I always said that was a "must". however - kids are a bit older now (3 and 6) and I've just gotten an application from a nice-sounding German girl who says she loves kids and they love her, and she has babysitting experience and small siblings, and is happy to help with housework cooking and to stay for a year, which would be very helpful.
Am I nuts to consider this? She sounds lovely but then so did our disastrous one - and there's no way for me to meet her in person before hiring. she has never been to the UK before, nor lived away from mum and dad for more than 3 months. but seems like the experienced ones are rather thin on the ground this year (we're not in london through in an attractive and "desirable" smaller city). And as we found before, experience is no guarantee, but at least it helps that they know more or less what they're getting into.