I've got a Sigma 150-500 OS and I've also got use of the wifes Sigma 120-400 OS and I highly recommend both of them. I did have a Canon 100-400 L when I got the 150-500 and after selling a body 1 of them became redundant. After lots of testing for IQ, IS/OS, failing light towards evening etc. I ended up selling the 100-400 (that was something I never envisioned doing when I'd just got the 100-400 as it was a teriffic lens).
The 150-500 is my 'go to' lens for airshow and wildlife and when coupled to my 5D3 it's an excellent lens overall. You can find lots of shots with it on my Flickr page and there's a few taken using a 60D. There's at least one 'bird shot' taken with the wifes 120-400 and I found that to be just as good for IQ and only very slightly slower to AF but it does handle failing light better due to it's f5.6 aperture as opposed to the f6.3 of the 150-500. Really the only difference is the range of 400 instead on 500 but on a 60D the 400 will give you a perceived 640mm, the only reason I stick with the 500 is that I use it on my 5D3 so I eeded maximum reach.
Either one of the lenses mentioned by the OP will give you great IQ on the 60D, or any other camera TBH, and your preference should be made on budget but keep the weight of the lens in mind when choosing. The 150-500 is quite a lump and the others aren't flyweight either but I can manage the gripped 5D3 and 150-500 all day handheld without any problems. Hope this helps.