Planning to go to Tanzania to do some voluntary work later this year, but want to minimise the costs by using miles.

There's availability to Nairobi with both BA (through London) and Swiss (through Zurich). I've got plenty miles for either, the timings are comparable and there's availability in First class on either (actually, Swiss would be Business out, F back, BA would be F both ways, but hey, either is better than economy on Kenyan I'd say?)

So, any advantages in going Swiss over BA, apart from burning through my BMI miles? Or should I go BA and keep the BMI for when it changes to Lufty ? I have to admit, I don't frequent the BMI board as much as I should - I don't really like trains that much, and the humour is better here.

Any hot tips for Nairobi (I might have a day or so on the way out and/or back, depending on timings and if it's worth a short stopover) ?

Any warnings about flying with Precision Air ?

Hotel recommendations ?

As always, I'm open to other suggestions, advice and warnings. I'm really quite a naive traveller - never been south of Spain, nor east of Budapest, and usually stay in IC or similar.