It also means that the horizontal space between those elements cannot be guaranteed to be exactly the same between browsers as it will depend on things like font-size word-spacing and browser defaults. The space will also be affected if the tags touch as the white-space will be negated or if a parent has a different font-size of has display of table which kills the white-space in some browsers.
However, in most cases the white space is not an issue unless you are going for pixel precision and then inline-block is not the best choice for this layout. Floats do not suffer the same problems with vertical-alignment or white space between nodes but of course have other peculiarities. Flexbox would also be useful here.