I rented the 70-300non-L once and did not find it much better than my EF-S 55-250 (other than build quality). The 75-300 is even worse that the 70-300non-L I believe. I would recommend them only if you are buying used or in a really good deal, as an intermediate better-than-nothing solution until you have saved money for the 70-200, or 70-300 or 100-400L if you want more reach.