Not sure yet which way I would go.I would love the XT2 or the 4/3system to be the answer( light ), but under bad lights, I don't think the 4/3 will hold up. The Sony A7 iii , or A9 looks like the game changers at the moment. This is the year and 2019 i will form my final kit. I am going to rent an XT2 , 50-140 kit before making any decision. I almost bought a 50-140 last week.
Wants not needs sometimes gets in the way. I have 3 grandsons now all involved in sports and want a set maybe a limited one to cover this.
If landscapes were all I shot the XT1 will do just fine, I have no beef with its IQ. Football is fast moving, erratic and usually under less than good lighting. They are all running backs , Tracking them is difficult Especially when players are coming through a pack. This is not a job for " kinda good ". Fast focus and focus tracking are two very different things.
Before all my injuries caught up with me all I shot was sports. One daughter played softball, the other was in dance all her life and was a flyer in cheer. In order to get " The shot " you need focus lock and tracking.
.Just thinking out loud again which is usually never a good idea. I still have my Nikon gear, just don't want to lug it around anymore. The D300 ,80-200 2.8 will track but it has gotten long in the tooth and it's abilities are getting rusty.
Just like bikes, Trek man Bob Bontrager wrote about parts. Light, strong, cheap. Pick any two. There's hardly ever a perfect solution.