I have had a chance to play around with Burundi bwayi that I bought a while ago ( bought 10 pounds of green two years actually!!). I roasted it to a variety of roast level from very light city roast to very dark Full City++ roast. I utilized this bean as single origin or blended with other varieties and brew it in a variety of methods from french press, aeropress, moka pot, vaccumn pot to ultimately espresso machine. I can say that I have a very favorable impression of this origin of coffee.
It is not a coffee that will wow your taste bud; its does not have any stand out attribute such as extreme acidty, heavy body, super fruitiness or agressiveness that I find in other origins of beans. However, what present is a very balanced combination of tastes and body, there are chocolatiness, nuttyness generally a coffee that anyone would like.
In espresso machines, it produces mild and sweet shot, great with small amount of milk but generally get loses my interest in larger cappuccino drinks. In espresso, I usually graviate toward more spiciness, bigger body so I usually tend to blend the Burundi with other beans such as a Brazil and a Sumatra and usually with my favorite Ethiopian. However, I love an Americano made with this coffee because it generally amplify the attributes of this coffee in comparision to other lower pressure brewing methods.
This coffee shine especially well in Aeropress; it produce a cup that is very reminescent to an Americano but with more clarity and sweetness; and by far, aeropress is my prefer method to brew this coffee.
Anyway, I have about two pounds of this coffee left and plan to roast and drink it till the very last bean. After I run of of these beans, I'm planning to look for more Burundi with similar characteristics.