in the past ive found no advantage to installing games on the 360, i dont know if this will be the case with this game though. if youve got the space then i would say go ahead and do it. dont know what changed on your ver as i have the pc ver.
I installed it to disk. Loading times are quick and the content streaming is faster. Asset streaming is still noticeable despite the install, but it's got nothing on Rage's content streaming.