I'll address your question - or issue - because I happen really love the first movement of Mahler 3. It is repetitive in the sense that the movement is basically a struggle between two opposing march forces: a tragic sounding, funereal march in minor; and a happy-go-lucky, quicker march in major. Of course, the "happy" march wins out in the end. But they do duke-it-out, back and forth, several times. In my opinion, what distinguishes this movement - aside from Mahler's kaleidoscopic orchestration - are two things. First, an incredible development section which leads to a climactic fantasy passage that Mahler himself dubbed, "the southern storm". Mahler also referred to it as "the rabble", and in one draft of the score he even penciled in, "let the battle begin". This passage is like hearing the battle with the King Rat from Tchaikovsky's "Nutcracker", but on steroids. Everything goes nuts, including independent, polyphonic parts for 7 or 8 percussionists (2 timpanists; snare drum - sometimes doubled; bass drum w/ mounted cymbal; triangle - sometimes doubled; tambourine - sometimes doubled; tam-tam). Anyway, "the southern storm" tapers off into an offstage snare drum solo which, in turn, leads to the recapitulation: a reprise of the symphony's opening fanfare for unison horns (which then leads to a reprise of our two opposing march forces). The other distinguishing feature is the coda. When executed superbly at a break-note tempo, the coda can lift you right out of your seat. More than anything, Mahler's outrageous, kaleidoscopic orchestration carries the day for a full half-hour. I never get tired of it.
Both the Ben. Zander and Esa-Pekka Salonen recordings of Mahler 3 have incredibly fast codas that are just thrilling to experience. But to get them up that speed, they also had to simplify the timpani part a bit. Timpanists simply can not play 16th notes on four different pitches - and hence, four different drums - at that speed. I don't always want to hear it done that way, but it IS incredibly exciting.