I spent a lot of time on this question when planning the end of my epic holiday vacation through Namibia and Botswana. The tour I was taking with Acacia Africa ended in Livingstone, on the Zambian side of the Falls. Should I spend the time and money to go to the Zimbabwean side of the Falls, too?
Your first view of the Falls in Mosi-oa-Tunya National Park is of the Eastern Cataract.
I ultimately decided yes, based on many factors.
But then the change in power happened in Zimbabwe, and all Peace Corps Volunteers were prohibited from travel anywhere in Zimbabwe. Peace Corps travel is indefinitely suspended to Zimbabwe.
So if you are a current PCV, the answer is easy: you have to choose Zambia.
I was underwhelmed by the Falls and too poor to enjoy the adrenaline-pumping activities on offer, and in hindsight a visit to both sides of the Falls seems unnecessary.
Simply put, most activities are available from both sides, and unless you have lots of cold, hard cash in the form of U.S. dollars, you can get relatively similar experiences from both sides.
Instead, I would choose one side of the Falls combined with wildlife drives in Chobe National Park just upstream in Botswana if you are looking for more to do in the area.
Things to consider when choosing which side of the Falls to visit:
Airport: Flights were cheaper to Victoria Falls, Zimbabwe, than Livingstone, Zambia, from Johannesburg. Kasane, Botswana, should also be considered as a potential airport. I believe transport between the airport and most hostels is comparable in Zim and Zam.
Cost into the national parks: To see the Falls in Zambia, the cost is $10 per person. It is $30 per person in Zimbabwe.
Location of town: Victoria Falls town is much closer to the Falls (practically in town), as compared to the Zambian side, where a taxi is required to get from town to the Falls.
Money: Kwacha, the official currency in Zambia, and USD are used on the Zambian side. ATMs have cash, as do money exchange locations. USD is the official currency of Zimbabwe, and ATMs are never guaranteed to have any money. You need to bring in as much USD as you might need (make sure it was printed in 2006 or sooner), although some businesses allow payment by credit card.
Visa for Americans: It costs $50 for a one-time visa to Zambia. It costs $30 for a one-time visa to Zimbabwe. It costs $50 for the Kazavisa, which allows double entry into both countries, but there are no guarantees that it will be available at any border. It was available in early January 2018 at Kazungula in Zambia. Botswana does not have a visa fee for Americans, but the country may be collecting a tourist levy of $30, payable by anyone who does not have a SADC passport or visa.
Activities: Like I mentioned above, the available activities are nearly identical from both sides (bungee jump, helicopter ride, sunset cruise, white water rafting). In Zimbabwe, the additional available activities include game drives in Stanley and Livingstone Private Game Reserve where there are black rhinos. In Zambia you can access Devils Pool, which needs to be booked ahead. Both sides have an activity I would not recommend: wildlife interactions. In Zambia you can walk with and ride elephants and in Zimbabwe you can walk with lions. Neither of these is good for the health of the animals.
Language: Both countries are former British colonies, so English is commonly spoken as a second (or third) language. I could not understand the local Zambian language, but siSwati and isiZulu speakers will be able to communicate with the Northern Ndebele speakers of Zimbabwe.
If you do decide to visit both sides of the Falls, I think a day trip to the other side is a better option if you can get the Kazavisa. A day trip allows you to walk across the bridge between the two borders, about a 2 km walk, for free and without a lot of baggage. If you have the extra USD, you can take a taxi from your hostel on one side, cross the first border, drive to the next border, cross the second border, and get a new taxi to the Falls or town. Expect at least $40 for the taxi option.
Overall, I think traveling to the Zambian side is easier for money reasons, but no locals expressed any safety concerns with traveling to Zimbabwe. If acquiring enough USD before travel is not a concern, and you are not a PCV or the travel ban is lifted, I would choose the Zimbabwean side.