Do you have any advice for potential travellers?
Ethiopia is really good for bird watchers. I wasn't really aware before I went, but this trip is likely to appeal to them, so it helps if you have at least a passing interest. We saw 282 species in 12 days. It might be worth Exodus having certain departure dates aimed at birdwatchers so you can get people with similar interests together.
The trip involves lots of different altitudes, terrain and scenery so you are likely to see some mammals. I hadn't expected it to be like in Kenya, but there are similar safari experiences when sitting around the fire in the evening at Awash.
Note that locals can pay to visit the hot springs in the forest at Wendogenet, and can be popular at weekends so may not be the relaxing experience you imagine!
There is no need to change much money as there is an ATM and currency exchange in the hotel in Addis. Its best to change back any leftover at the hotel as the airport exchange may not be open if you depart on a late evening flight. Food is generally cheap and its good to buy bread, fruit etc on the road. The set menus at the hotels are their take on what they think Westerners eat, and can be very repetitive, so eat locally when you can.