Just because one doesn't generate an income, doesn't mean they shouldn't or don't strive for the best.
I too love the 200 f/2 and the older F1.8 from the results I've seen, I cant offer experience with either option, but I can relate to your desire.
Everyone is different and ever since switching to 5D Mark III and started buying L glass, I can clearly see the difference in quality. It might take me 2 months or 2 years to come to terms with spending 6k on a glass, but when the time is right, I want to be ready to pull the trigger. I really don't want this thread to turn into why L glass or tele primes are waste of money for non-professionals so I'd like to not go into any further discussion regarding this
Someone made a comment about the weight of 200 F2.0 and how it would not be trivial to carry it around all day. I see that it's about 2 lbs heavier than my 70-200 IS II, and I don't think that'd be a problem (I'm a pretty muscular guy:P).
My only worry with 200/2 is it's a bit older model than 300 2.8 II and I'd be going nuts if Canon replaced it a year after I buy it with all the new features (like the 3rd IS Mode).
I do wish that there was a way to try out these new lenses without having to pay hundreds of dollars (I just think renting a lens is such an expensive thing that gets close to being a waste of money [UNLESS you do it for business where you can offset that cost with the money you make]). I wonder if I were to stop by B&H/Adorama, would they let me try one on in the store?
Lastly, are there any real life shots that compare 70-200/2.8 to 200/2. I'm curious to see 2 things, the difference of F2.0 vs F2.8 in terms of DOF and the IQ at the same aperture. I know that prime is a full stop faster which might mean the difference of ISO 6400 vs 12800 or 1/500th vs 1/1000th, which is a huge difference, but how does that full stop translate into real world photos when there is plenty of light? For instance, My 85L produces such photos that I can easily tell they were shot with that lens and not with a zoom, but then that's F1.2, a full 2 1/3 stops faster than 2.8. There isn't that much difference between F2.0 and F2.8.