Nicholas McGegan has conducted some excellent Handel recordings in the past and is something of a specialist in this repertoire. However, his recording of "Messiah" leaves something to be desired. There is a lack of feeling that pervades the entire piece -- everyone does a thoroughly professional job, but it ends up sounding like just that: a JOB.
It's really a pity, because McGegan goes further in his scholarship than do other conductors by including nearly all the variants which Handel wrote through the years for different performances of the oratorio. So we get not only the 4/4 version of "Rejoice greatly" but the lilting 12/8 version as well (which I prefer). There are four versions of "But who may abide" and "How beautiful are the feet of them," three of "Thou art gone up on high" and a soprano version of "He was despised." The list goes on.
The performance itself, however, simply cannot compete with other recordings. The choir has a light, pleasant sound but is placed too far back, and the sound as recorded is boxy with very little "air" around the voices. All the soloists are capable and unoffensive, but uninspired as well. Only Lorraine Hunt really comes to life singing the alternate soprano version of "He was despised," giving a reading both luminous and heart-breaking.
If you are looking for a really fine period-instrument recording, I can recommend three: John Eliot Gardiner's, Trevor Pinnock's (with superb soloists in Arleen Auger and Anne Sofie von Otter) and Paul McCreesh's more recent version with one of the strongest line-ups of soloists I've heard in a long time. Also worth looking into is Richard Westenberg's recording with Musica Sacra, easy to overlook. It contains the 12/8 version of "Rejoice" and the soprano/alto duet version of "How beautiful are the feet" and the following chorus, "Break forth into joy." The soprano soloist is the marvelous Judith Blegen, one of the best. Compared to these four recordings, McGegan's is an also-ran. Buy it for the scholarship and the extra music, but get another version to hear an actual performance of "Messiah."