Well yeah. don't bother with the full length version. even listening to it in sections at a time. Parts of it is the same thing repeated over and over for multiple hours.
Just get the single disc-length version, it's great. It plays more or less like a proper lips album. Like 50 minutes of Embryonic all segued together or something. It genuinely does feel like 1 long multi-part song too (kinda like Thick as a brick does for instance), and not some album-length medley-a-bunch-of-songs-together flower kings/dream theater bullshit.
The 6 hour song is worth exactly 1 listen for the novelty factor. it's ultimately not as good as the 24 hour song, but there are many cool sections and neat jams (especially in the last hour). the 6-hour length is just short (ha!) enough that it's actually possible to hear it all in one sitting. Don't force yourself to do it if you don't actually want to.