I didn't actually go on my flight as it was cancelled only 6 hours before take-off. So, I can't review the flight itself. However, I can comment on the customer service, or lack thereof.
Upon learning that the flight was cancelled, I phoned the customer service center who told me that the flight was simply delayed and not cancelled. Moreover, if it was cancelled, they assured us that they would put us on another flight and thus should go to the airport as normal. We even got them to send as much in an email.
Upon arrival, our flight was indeed cancelled and not delayed. We went to the ticket station in the airport. Here, we were told that they could not do anything. They could not find us another flight on one of their partner airlines, nor offer us a refund. However, another customer was able to get a flight to the same place we were trying to get to. So, it didn't seem like they wanted to help.
At the end of it, we had to book totally new flights to get to our honeymoon at our expense, of course.
Right now, we are trying to get a refund. However, no one answers their emails and the call center does not pick-up either. Apparently the refund is 'pending', however this is not to be trusted.

Flying with Kenya Airways was my first and last. I discovered the hard way that they are prone to delays, aren't
very accountable, and often lose luggage. After losing my luggage they were able to find it but delivered it to me with a broken handle. Filing a claim requires you to send an email and wait a long amount of days (no set amount of time) before and if you hear anything back. Calling customer service will just result in people muting the phone to pretend that there are computer issues or they will just tell you to send an email. Worse airline that I have ever flown.

Never fly this airline from US to Kenya. 6 hours delayed first flight 3 hours delay return flight. No communication. From Nairobi we sat in an hot stuffy holding with no water and no communication from any staff. Their service is absolutely the worst. Fly any other airline.

None of the entertainment screens were working during the entire 9.5 hour flight. Cabin crew said they hadn't worked for ages and weren't sure whether they'd be fixed.

On return journey, we went from Zanzibar to Nairobi, however, at the airport, we were told they were overbooked by 11 seats in economy. However, they had 10 available seats in Business but you had to pay for them. As we were travelling on from Nairobi back to London, we didn't want to miss our flight so reluctantly agreed to pay. But they refused to take credit cards (they clearly didn't want a paper trail) and said it had to be cash only. Cue 11 people running out side the airport looking for ATM's. Found one that didn't work, found another and it took several attempts to get the money out. Dashed back to airport only to be told it had to be US dollars and not their own currency - Tanzanian Schillings! Informed them that you couldn't take US dollars out of the ATM which they knew full well so was met with a smile and said they'd exchange it themselves for US dollars but the rate they'd give us would be ridiculously low. We were held over a barrel and they knew we had no choice!

Never again, will we fly with this dodgy airline!

I strongly advise against traveling with this airline. My recent experience on December 22nd traveling from Johannesburg highlighted significant reliability issues. My flight from Nairobi to Bangkok was cancelled during boarding, resulting in substantial delays and adding one to two days to my overall travel time.

Upon receiving the cancellation notification, I immediately sought assistance at the OR Tambo International Airport counter. The customer service I received was unacceptable. The consultant's demeanor was unprofessional, dismissive, and unhelpful. This indifferent attitude seems pervasive among the staff, creating an environment where passengers feel powerless and disregarded. It's crucial to remember that as paying customers, we are entitled to respectful and efficient service.

The accommodation offered in Nairobi was poor and inconveniently located far from the airport. The limited rest time provided between arrival at the hotel and the subsequent departure further exacerbated the difficulties caused by the flight cancellation.

Furthermore, the airline's practices regarding flight upgrades and prioritization are questionable. Fees are charged for upgrades and earlier flights, yet it appears that some of these advertised flights do not exist, resulting in unnecessary expenses for passengers. The airline operates only one flight per day on this route, making the paid "convenience" options misleading.

Based on my negative experiences both on my outbound and return journeys, I strongly recommend avoiding this airline. The inconvenience, poor customer service, and questionable practices make it worthwhile to consider alternative airlines, even at a slightly higher cost.