I'm using Canon EF 70-300mm f/4-5.6 IS USM and I'm very satisfied with results. People call it "hidden L". Well...it's not an L lens but it gets the job done. It has 3 stop IS (according to Canon) and it's very useful in moody Vancouver weather and in low light situations. I was getting nice results with shutter speeds as low as 1/30 on 300mm with IS on. It has MF and AF of course and IS has two modes 1 and 2. No2 is for panning.
I'm using it on XTi and you'll probably get way better results with 60D.
My next main lens for birding will be 300 F4 IS or 400 F5.6 but 70-300 stays in the bag
There's lots of reviews online, check them out.
Hope this helps.
P.S Are you satisfied with 400mm on 60D?
Thanks for the info!
I am very satisfied with the 400mm f5.6 on the 60D. If you get the 300mm f4 with a 1.4x you will get a focal length of about 420mm, but the autofocus will be much slower than on the 400mm 5.6 and the sharpness will be degraded. You can also use the 300mm f4 by its self and get fast autofocus and good sharpness, though it still won't be as sharp and fast as the 400mm f5.6. In my opinion, if you are thinking of getting one of those two lenses (like I did), you should go for the 400mm f5.6.
I just recently got my Canon EF 400mm f5.6L USM lens. I am shocked. It is much better than I expected. The photos are tack sharp. The manual focus is perfectly smooth. One of my favorite things about this lens is that the autofocus speed is like lighting. This is surprising as this lens has an aperture of 5.6. Another great feature of this lens is the lightweight. The Canon 400mm F/5.6L weighs just 2.7 pounds, enabling you to take handheld photos on most days (all days with some sun, or even bright days without sun). The price is also great. I think the right price of this lens (new) should be about $2000 or more, but that is not the case. You could be able to get this lens new on some websites and stores for $1,200.
-Super fast autofocus
-smooth manual focus
-extremely lightweight (can be used handheld)
-can focus fairly close (3.5 meters)
No IS (image stabilizer)
I hope this helps!