Truly a once in a lifetime experience!
We can't wait to return!
This, we will never forget!"
A guide who has lots of experience!
I just got back from 15 dd of safari that included some trekking. The company is Restoration Safaris (https://www.restorationsafaris.com), and it's locally owned and operated out of Arusha. They created a custom trip for my partner and myself. We had the vehicle and guide/driver all to ourselves, and could linger as long as we wanted. All safari vehicles have a roof that pops up into a shade so you have a 360 view from high. It was really great- we saw hundreds of elephants, handfuls of cheetah and lions, a leopard, scores of giraffes, hippos, all kinds of birds (lost on us as we're not birders), and the Great Migration. Every day seemed better than the previous. We were probably spoiled with Tarangire and Arusha NPs by the time we got to the Serengeti, where, as in Ngorongoro, animals are really far away (prob. need at least 400-600mm to get them, at which point you're doing animal portraits only, not really recording your experience of what you see with your naked eyes). The animals we saw in Tarangire were either much closer or in a more interesting environment.
One thing in choosing a safari operator is to make sure you find a guide who has lots of experience- to be able to predict when and where animals will show up; and contacts- drivers tend to tip each other off on animal sightings to help each other out. It's also important to find one who's passionate about getting you to see amazing things, and who's good at reading your interest and energy level so he can get you what you want. On our last day, with a 10AM flight out of the airstrip in the bush, our guide convinced us to go out at 6am for one last game drive- plenty of time to for breakfast and to catch our puddle jumper back east. And when we saw our first cheetah no more than 20 ft from the land rover, I don't know who was more thrilled- us, or him, hearing us babbling and going crazy.
Our accommodations were all very nice, clean, and comfortable, and not necessarily high end (we wanted to keep costs down). But you should know that safaris are expensive: locals don't do safaris the way westerners do them, at least in Tanzania. It's all a question of logistics- getting you from spot to spot, food, water, etc. All that's carried in, and it's not as if there's an existing infrastructure. We never felt unsafe during our trip, which included an 18-20 mile trek over 2 days and walking safari (aka, hike in a national park), etc.
One thing you might consider is whether the company is locally owned. I like that all of my money was going to a local company- the more Tanzania benefits from safaris, the more it will work to preserve its natural habitat. The company also donates trees to plant in local schools.