We took a couple "regular" taxis in Lima, including our first memorable once from the airport to Miraflores at 6 am, and we were fine. Just before exiting the arrivals hall, we found that the Airport shuttle bus, which I had booked in advance, wasn't open yet. We ended up paying for and getting a Green Taxi. It was the WACKIEST ride ever--Lima traffic is absolutely nuts! All the cars were so close together, you could reach out a hand and touch the car next to you. Absolutely insane. But we got to our destinations just fine. We kind of look at it as part of the adventure.