Advantages of the 05:
...the Leather seats are MUCH more comfortable that the cloth ones. I made that choice when I was test-driving 05s before I bought mine. The difference is not just the leather, the seats themselves are completely different. The leather seats are not automatically heated though.
...If you have a conversation with someone and the topic comes up that you almost spilled your drink while driving to work...the KJ cloth seats will actually stain. Doesn't matter what your proximity is to the Jeep, they'll stain.
...the rear seats of the 05 lay "flat." They are not completely flat, but much more so than the pre-05s.
...rear cargo light
...Full-time 4WD (very nice on rainy pavement)
...It has cool step side bumpers that hang so low people will think you've figured out how to do a body lift on a KJ
(Internet Forum Lurking Vulture Disclaimer: This comment is meant for humor-related purposes only, any other use will void any and all implied and/or inferred warranties on said statement and will render the non-humor-related user retar....err, "Challenged.")
Advantages of the 04:
...Tow pkg (extra cooling)
...Fewer miles per year
...I like the color better (I don't hate the white, just like the green better)
...I like the rims better (I want to be nice here, but I really just don't like the rims on the white one)
Unknowns:
Does the 05 have Traclok rear?
Does the 05 have heated and/or power seats?
Does the 04 have an OS handle in front of the passenger seat, or just a flat dash?
Did the 04s come with passenger aware (whatever it's called) airbag system? (my 05 turns off the passenger side airbag when there is no one in the passenger seat and when there is something lighter than an adult)