I got mine in 2009 and it still dazzles me. Still. The uniform sharpness, the contrast and colors... the iamges stand out even in thunbnails. I don't get why or how. they just do.
There are obvious reasons to get primes. But in context of shooting, in live events, the 70-200 is so versatile. I remember swapping between my 50 and 135 at an event.... Nutz!!! then I borrowed a sigma 70-200. Very functional to being able to zoom. However in any non-live event, or one where you don't require to change your field of view often, the 135 will just shine!