What are the main differences between these lenses?
The obvious advantages of the 28-300mm are (a) the extra 7mm on the wide end and (b) IS.
The obvious advantages of the 35-350mm are (a) about 10 ounces lighter and (b) a whole lot cheaper (when you can find it selling used)!
But...does the 35-350 sacrifice much in terms of image quality (minus the IS considerations)?
I'm also curious how the 35-350 would stack up to the 100-400mm (if anyone has any real-world feedback). I've had an eye on the latter for a while, but I started to realize that I don't think I need that extra 50mm....but I sure could use a nice all-in-one outdoor lens for my backpacking adventures.
Thanks in advance for the feedback!! 
