These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: Many of Delerium's fans weren't too fond of Poem or Chimera, although for some Nuages du Monde wasn't particuarly fantastic as well. For other long-time Delerium fans, they were less then happy when Delerium went from being dark, moody, ambient music; and began becoming very mature electronic pop-oriented. Of course, most of their fans didn't care and kept on listening.
The same can be said about Conjure One, which is a side project of one of the members of Delerium. The album "Extraordinary Ways" was well-received by critics and sold exceptionally well, many of the fans weren't too blown away, expecting for Rhys to rehash the debut album.
That One Song: Delerium has many fantastic tracks in their library of music, but most people became aware of them when they collaborated with Sarah Mc Lachlan and created the single "Silence" which has bought a lot of attention to Delerium and been remixed an obscene amount of times.
The Other Darrin: Many people confuse Delerium with Enigma, Deep Forest and Future Sound of London. It didn't help that Delerium prominently re-used elements from Enigma and Deep Forest's debut albums (1991 and 1992, respectively) for their 1994 album Semantic Spaces. Early 2000s file sharing programs such as Kazaa and Lime Wire saw a proliferation of mislabeled tracks from all of these bands.
Other projects by Leeb and Fulber, including Conjure One, Synaesthesia, Equinox and Intermix often get lumped in with Delerium.