Searching for a telephoto lens - help!

[shannonegg]

This is my first thread and am hoping for some good advice. I recently bought a Canon Rebel XTI and have realized my love for shooting action (mostly kids sports). I am borrowing a telephoto lens from a friend, but want to purchase one for myself. The lens that I'm borrowing is a Sigma 70 - 200mm with 1:2.8 APO. The Sigma is great, but not if this is the most appropriate, or could I get the same results at a lower price point? Also, this lens does not have an image stabilizer - will I notice a big difference with a lens that includes this feature?

[Canuck935]

Image Stabilization is especially useful with longer focal lengths. If the 70-200 is a bit big and heavy and you like the range, then perhaps look at an f/4 version. Check out Canons 70-200 f/4. I believe it comes both with and without IS depending on your budget.

[freygr]

Just remember you will need the F2.8 glass for evening and indoor events. Unluckily that kind of optical speed is costly.

[SmartWombat]

Also remember that IS is only useful for static subjects.
Doesn't help if your subject is moving, that includes nodding the head, waving the arms.
Another argument the a wider aperture - and spending more money (sorry).