Is traveling with Matatus in Kenya risky?

Hello
I am taking a trip to Kenya in a couple of months with some friends of mine and we have heard that the best way of getting around Nairobi is matatu, something like a shared taxi. We were wonering is traveling with it in Kenya risky? Have anyone experienced it?

Hello
a couple of friends of mine and I have traveled to Kenya last year and we had a great time in Nairobi. We tried matatu and we didn't think it was dangerous. I mean it is the cheapest transportation around the city and it is really good considering its price.

Hello
a couple of friends of mine and I have stayed in Nairobi last spring and we were totally amazed by this place. Matatu is really funny way of transportation and I thought it might be dangerous because of the bad roads in Nairobi and the fact that no one respect traffic signs or no one knows them...