Part of the fun of a safari is feeling transported back in time. The savannah is timeless and, even in 2014, you can camp in a canvas tent just like Hemingway. That said, you might not want to, and that's fine. Certain niceties can significantly improve your experience. Here's what to look for:
Airport Pick-Up: A truly plush adventure begins the moment you land in Arusha, Dar es Salaam, or Nairobi. When you see the chaos waiting on the other side of the baggage claim, you’ll be glad you paid a bit extra. Realistically, you’ll want a guide for the whole process.
Daily Briefings: You want to know what's happening. Make sure that your outfitter puts a major emphasis on keeping clients informed. You do not want to be treated like a passenger and you'll want to have a say in changing your itinerary mid-day.
Safety Measures: Fly-in doctor service is offered by every serious outfitter. There aren't going to be hospitals nearby so this is absolutely critical, especially if you suffer from medical conditions. Serious companies will offer to help with travel insurance.
Personal Stewards: Sure, this is a bit much, but if you’re going to splurge you should expect some handholding. Stewards actually provide greater flexibility by being your wingman, escorting you back to your tent when you’re drunk, and helping you communicate with locals and guards who often have great stories.
Electrical Outlets: You might want to escape the modern world while you're in it, but you won't when you’re not.
Flexibility: If you're paying a lot (and you should be), the tour company should be willing to work with you to make a trip perfect. If the company ever says, "No, this is how we do things," look elsewhere. They are likely understaffed or lacking in infrastructure.