I have both, though the 70-200mm only for a couple of months.
I'm pretty sure the 70-200 is better, but it's twice the price! (not twice the lens though).
I often use these lenses at fairly close distance, long end, wide aperture (zoo fences); this is why I thought I needed the 70-200.
I used to get very decent results with the 80-200 by backing off the long end down to 185mm. From what I now know about the 'breathing' of the 70-200, I am probaby getting less than that anyway with my 70's '200mm'.
Before I got the 70, the 80 was my favourite lens, it really looks like quality kit, and the results were almost always excellent. I am still unsure if I made a good decision.