« on: April 05, 2013, 09:38:17 AM »
Over the past 20+ years I've had two 300mm f:2.8 non-IS lenses. In that time they've been the source of much if not most of my published, as well as personally favorite, work. In fact, I'm convinced that, during the interval I was without one, the quality of my photography suffered. Between the sharpness (on par with the best of L primes), its shallow depth of field and pleasing bokeh, is that good a lens that it is almost certain to make a better photographer out of you.
That said, there are reasons to be cautious about purchasing one. Almost all are 15 or more years old now, and some are as much as 25, making the availability of replacement parts an issue. I don't think FBW, by itself, is too much of a problem, but, rather, that Canon no longer supports this lens. You will need to find an independent source that's sufficiently skilled and resourceful to perform repairs, which, depending on where you live, will be anywhere from a moderate challenge to being totally out of the question. Case in point, a couple years ago, I needed to replace the rear mount. Pretty straightforward, right? Seeing that I couldn't get the part from Canon (and I'm a CPS member) so I could fix it myself, I took it to this area's best repair shop (I live less than an hour from Minneapolis-St. Paul). It turned out to take more than a couple weeks, as they had to order the part for a 300/2.8 IS, then, when it came in, machine it so it fit. Something to think about as you consider this lens.
What I hope to convey to you is that I highly recommend the 300mm f:2.8 non-IS. Few, if any, other lenses or cameras would give you as much "bang for the buck". But, be aware that, if it breaks, you may not be able to get it fixed. And, seeing how much you're almost certain to develop an attachment to this lens, THAT could be your greatest problem.