We visited Masai Mara Reserve and Nakuru National Park in July this year, so apologies for the late review. As others have said, there are two parts to the safari: the organizing and the guide who takes you on the safari. We had Rachel from African Habitat Safari Holidays, who organised everything for us and Obama was our guide for the 5 day/4 night safari.
Rachel is a professional. She knows what she is doing and is very good at putting together an itinerary based on your needs. 

If you want to find yourself amazing new friends in Kenya, not just a business selling a service, this is the tour agency you need to contact.
And I mean it! My 10 days solo trip to Kenya became a trip of a lifetime, mostly thanks to African Habitat Safaris. From airport pick-ups and drop offs to everything else during my 6 days safari (Masai Mara, Nakuru, Naivasha, Amboseli), all was amazing, comfortable and safe.
Rachel is the super hero, the one that had to deal with all my 30 emails during 2 weeks and she handle it brilliantly, with patience, understanding and commitment to help me organize a dream trip, keeping in mind also the budget. And so we did! I am serious about coming back to Kenya and see my friends again. Thank you all! You’re best!

Except for a minor misunderstanding about airport pick up…which was taken care of and solved quickly…everything went perfect. We had ordered a 5 day private safari and during the whole planning we had a good cantact and communication with Rachel and Simon in Nairobi.
Our driver and guide Simon, picked us up at our hotel and followed us all 5 days and gave us a fantastic experience. Being very uncomplicated and flexible, he did his outmost to fullfill our wishes and telling us about the things we saw and the life in Kenya both within and outside the national parks. So thank you Simon for choosing the most bumpy roads in Kenya :0)…Thank you for kicking us out of bed too early in the morning :0)…Thank you for sharing the car with 5000 flies from the buffalos :0)…

We went on a 4 day safari in Masai Mara and Lake Nakuru. We had wonderful time. We found African Habitat Safaris from another web site and connected via email. Rachel was very helpful and reliable since the beginning. We could see the five big and witness amazing scenes in Masai Mara. Our guide and driver (Johannas) was great. He was always at the right place at the right time. We highly recommend African Habitat Safaris.

Our group was very well looked after by the team from the time our flights landed in Nairobi until we got dropped off at the end of the tour. Our guide George was highly knowledgeable about the landscape and the wildlife, as well as friendly and fun to spend time with.
We had options and flexibility, the add ons are optional, and staff are not pushy about this.
I’d happily use the same team next time I return to Kenya for this type of trip.