There are several long drives along dirt roads, the longest being between Debark and Axum which is a full day. Most of the time the route is along very scenic mountain roads (I had no idea Ethiopia was so mountainous) . The problem is not with bumpiness - for dirt tracks they are realtively smooth - but the dust. Even in December/January we had to choose being hot and stuffy with the van windows closed or be choking with dust. In hotter times a face mask might be a good idea. (This suggestion is untested but offered in good faith!).
I opted not to go on the mule trip in Lalibela, though those who did cerainly enjoyed it though some found it a tad strenuous. If you choose, like me, to spend a relaxing morning in Lalibela look out for the art gallery just down the road from the hotel where a talented young artist named Tegryne Vitedain will offer to sell you one of his quite charming water-colours. You will probably get two for the price of one as he uses both sides of the paper!
Do try 'tej'', a drink made from honey, not unlike mead.
I'm a bit fussy about coffee and have to say that the Ethiopians take it very seriously. From espresso machines in hotels to the long but lovely coffee ceremony I was never offered a cup of coffee that was less than perfect.
With all it has to offer I have no doubt that Ethipia will become a major tourist destination. Roads will be improved and services become more reliable and some travellers might like to wait for these things to happen. But to you intrepid and adventurous souls I would say that now is the time to go.
There's a wonderful misprint iin the trip notes. In the reading list Wilfred Thessiger is renamed Wildfred. I don't know what he would have thought but it made me chuckle! (Let's not tell Exodus - they might correct it)