A couple of months ago, I was at an indoor hockey game watching and taking photos of my bosses kids playing. Along came a gentleman with the 300/2.8 mounted on a 1D Mark xx (can't recall) which in turn mounted to monopod and the conversation started:


me: Wow, great rig, love the lens


him: Thanks, she sure is.


me: You know, that's one of my dream lenses.


him: An awesome lens and great for those tight shots


me: Not sure if it deserves to be on my little Xsi


him: Why not, but you will be snapping up photos of this game from the parking lot


me: LOL


him: Besides, unless you plan on making money (as he is an actual photographer), this lens deserves to be utilized on a FF or an APS-H camera, your choice of the 70-200 2.8 is a good choice.........


Suffice to say, these guys in these forums are correct and do know what they are saying, stick with the mentioned lenses and you won't be disappointed. But hey, if you've got the dough, the sky's the limit!