I love the 28-300L lens. If you are doing professional shoots, maybe it's not the best (slower lens), but under nearly all conditions i have had an awesome time with it. I travel and hike a lot, and it's great to have a mostly all-around lens. On the 7D the wide end is not so wide, but the long end is really long (I take a 10-22 with me to get wider). It's a little heavy, but that can be accommodated for with the right strap (black rapid is great for me), and people will notice it - i've had several people come up to me and comment on the lens or ask how much i spent on it, so i am disguising it a little by putting some bike handlebar cork tape on it in different colors, and that also helps with the locking ring which is metal, but with the tape it's really easy to lock/unlock with one hand. Over two years of mountains, beaches, sand dunes, rain, desert, etc, never had any dust problems inside the camera. Some sand got in between the barrels and made some grinding noise, but a rocket blower got it out. The IQ is good enough for me, and I have blown pictures up to 60" and looked great. I'm not a professional and don't pixel peep much, but for myself, as gifts to other people and putting up at art shows, you can make some really nice, large images with this lens. Bokeh can be achieved with your subject well in front of a background, and the 2.3 ft focus distance does make it close to macro-like (though IQ is much better with dedicated macro). And if you're worried about changing lenses in the field, this is a great one to have. I rented one before buying (and a 100-400 to compare) from some strange place called lensrentals, and sealed my decision almost immediately.
Cool, thanks for the feedback! I assume the pop-up flash on 60D/7D would be blocked or cast a huge shadow due to the size of the lens, right? I know this is an issue with the 17-55 lens, but I'm almost always using an external flash head with it anyway. Of course the 28-300 is a much bigger beast though.
Hmmmm...and did you do this 'research' by placing various bodies with a 28-300L mounted inside a two-chamber isolator, with colored indicator smoke, to trace the air flow? Or read a document describing such testing?
Haha, no. But one guy DID mention experiencing more sensor dust when he used push-pull zooms as opposed to regular ones. HOWEVER, these were on old bodies- 10D, D60, etc...not sure if current models are much better sealed than those were. (plus I know the older bodies didn't have the auto-clean feature, not sure how big a difference that makes)
The 5DII and 60D have the same level of dust resistance, and I didn't notice and dust issues with the 28-300L.
It's certainly not a cheap lens, but consider - the IQ is equal to the 24-105L, and it's an 11x superzoom. That's very good IQ in an absolute sense, and unmatched in a lens with that range.
Still, I don't think it would make a good one-lens solution, for me, on APS-C. On FF, though, it's great.
The 24-105 is a great compromise/walkaround lens for me and delivers decent, if not outstanding, quality. However, I find 105 to be not long enough for a shot MUCH more frequently than I find 24 to be not wide enough for one. But I also know that there is a noticeable difference between 24 and 28...just like there is between 17 and 24- on crop, 17 (for me) is a must for any tight indoor shooting. For outdoor events or travel, 24 is usually sufficient.
For the type of shooting I enjoy, I like the extra reach I get from the APS-C sensor. I could never give that up for FF, personally. Eventually, I might look into trying one out, or I may just go ahead and take the plunge.