I always thought that having it later than FW gave the girls a chance to fatten up after getting uber-skinny to walk in the high fashion shows. Although I must admit, and I am a big critic of super-skinny models, that last years show was very thunder-thigh-y, perhaps because a lot of the models just gained weight without exercise and the extra mass was jiggle as opposed to muscle.
Also last years show seemed to have extremes, on the one hand you had models who looked liked jail bait (Abbey Lee Kershaw and Behati Prinsloo) and women who looked like cougars on the prowl (Ana Beatriz Barros and Candice Swanepoel, although I don't think that they are as old and rough looking as they appeared in the show). For some reason and perhaps it is unfair, but I exempt Heidi, she is a VS institution. The problem is that half of the models looked like her contemporaries and the other half looked like her daughters.