In addition that the code you consider including should have high enough quality, it is also important to consider external dependencies. If the library require

In addition that the code you consider including should have high enough quality, it is also important to consider external dependencies. If the library require 35 external dependencies, it is likely to be a maintenance burden in the future, so you better avoid it. Otherwise you may end up in the situation where A upgrade to use version 2.0 API of library C, while library B continue to use version 1.3, and now you sudenly have a compatibility problem. Other factors can be if the library is hard to build, or is only for windows while your product is for windows, mac and linux. The real question is what will create the least maintenance burden in the future.