I have not read Jude much with attention to his style:
my concern with Jude has been more exegetical,
doctrinal or theological. Therefore, I'll post what
A. T. Robertson has to say about this Bible book's style.
(1) Jude has "a rugged rotundity of style that is
impressive and vigorous, if a bit harsh" (A Grammar of
the GNT, p. 124).
(2) Jude shows a willingness to employ both metaphors
and triplets. His work is more Hebraistically flavored
than James' epistle.
(3) While some have asserted that James does not have a
"command" of Greek grammar, Robertson states there is
actually "little that is peculiar in [Jude's] grammar, for
he shows the normal use of the Greek idiom" (125).
(4) The optative mood occurs twice in Jude.
(5) "Cases, pronouns, tenses, free use of the
participles, indicate a real mastery of current Greek"
(6) "Deissmann (Light, p. 235) considers Jude a
literary epistle in popular style and 'cosmopolite' in
tone (p. 242), with a certain degree of artistic
expression" (Robertson, 125).