It's hardly surprising that the timing is pretty much the same, as they are both settings of the same poem. As to the tune, for me Darke is the better of the two, and was the one I was brought up on at school. As a choral singer I have sung both versions over the years (the Darke, sadly, less often) and have never really liked the Holst version.

There are, of course, other versions of it, most notably Benjamin Britten's as part of his work "A Boy is Born". More recently a new setting was composed by Robin Doveton