I settled on the Canon 70-300 mm f/4-5.6 IS USM mostly because it was the right price. Canon had it's annual Best in Glass Sale and it was reduced $250 to $399.99.
Of course there are higher quality lenses, but I didn't feel like breaking the bank for a lens that I wouldn't be using an awful lot (my primary lens being my 10-22 mm f/3.5-4.5 USM). It had reasonable reviews which was good enough for me.
I only took a few shots in the store. I'll practice with it sometime when the weather is nicer outside. I'm sure it'll suit me fine.


