Ok... since no one has really answered the question the way I want it...
Let's rephrase it...
There are 3 70-200 on the Canon market...
one is 4.0-5.6 (I may have the numbers wrong, but it's in that range), and 2 are 2.8.
The 4.0 is very affordable, but not suitable for my needs (need fast speed).
One of the 2.8 can be affordable with a loan, the other one, not so much....
So basicly, the 2700 $ lens is not so much an option, and the 4.0 either cause too slow.
That leaves me with the 2,8 at 1300 $..
Or..... within the same price range..
The 100 macro 2.8
I know I was not always shooting at 200 mm on the show ring (horses I mean), and sometimes I was just shooting wide and cropping the image on PS afterwards, cause it was more convenient.
It is hard to have the focus point exactly where I want it, when the horse is galloping and all..
I may rent the 100 2,8 macro and try it out at a horse show and compare...
What do the pros here think about that?
This is an example of photo taken with the 2700$ lens:
http://farm6.static.flickr.com/5066/5774444958_7f58bc2fdf_z_d.jpg
If you found that you were more likely to shoot somewhere in the mid range like 130-170mm I would actually say get the 135mm f/2.
Obviously, some advantages, the extra focal length and the extra speed. However, in this is also the problem of the extra focal length. When you don't have enough you can crop it down, but with too much you are kind of stuck.
The 135 is ~1,000 so not out of your range.
And yet another option, just to make your decision harder.
If you don't want to break the bank I would suggest this.
It's kind of the best of both worlds. The 100mm focal length and the f/2. However, it's not an L lens and obviously has a bit less in the IQ department.
Compare the lenses and see what you think.