So I have a dilemma I was hoping you would all assist me with. I recently was getting to set to buy a Sigma 50-150 f2.8. The theory was that it would act as my moderate-range tele with a nice bokeh for portraits, and complement my (Canon 7D) lens collection of 50mm f1.4, 15-85mm f3.5-5.6, 35mm f1.4, & 85mm f1.8. However, a recent craigslist ad in my area popped up with someone selling a (apparently top quality condition) Canon 35-350mm f3.5-5.6L for the exact price as the Sigma. Now I understand they are vastly different products, but I'm a relatively poor student and can't afford both at this time. On one hand, I want something fast that has some range and will deliver a decent bokeh. On the other hand, the flexibility of a 10x zoom with very good image quality reviews for a bargain price is very appealing also. Here's what I know about these two products: ====Sigma 50-150mm f2.8===== PROS: -Fast 2.8 -Has a very useable range -Nice bokeh from 9-blade -Good build quality & product quality Cons: -Reportedly has front-focusing issues on some copies -150mm is only a moderate tele range -Sigma tends to lose value faster than Canon -No IS ====Canon 35-350mm F3.5-5.6L==== Pros: -Epic 10x zoom range, for use as a solid walk-around lens -Legendary L series build quality & value -Relatively inexpensive compared to it's book value -Has the 72mm filter size that my 15-85 shares -Good compression from 300mm Cons: -Relatively slow lens -Sharpness does suffer overall for zoom range -Less exciting bokeh at 50-150 range than Sigma -Also no IS --- So that's about it. Anything you would like to add or what your choice would be, I would greatly appreciate hearing. I have a couple days to choose so I'm hoping to get a ton of feedback from the veterans here. Thanks in advance!