I'm used to my size of camera so even the XT2 + 18-55 will be a significant decrease in size. Don't care much about the weight though as I don't mind the weight.
Just last week I was going through some of my photo equipment, and I picked up my Canon Rebel for the first time in months since I got my Olympus EM1. The size difference was hard to believe. Felt like the difference between a mandarin orange and a grapefruit. (Ok, so I may be eating a mandarin orange right now and thought it was a good comparison.

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After owning the Oly EM1 for 1.5 years now, I've often thought about Fuji, lately the XT2, as well. What is your driver for wanting to change specifically to Fuji? You've mentioned wanting to be inspired again, as well as weight. So, why specifically Fuji? I'm not trying to change your mind, I'm trying to figure out why I have the same thoughts on changing, haha. For me, I'm wondering if it's GAS, "grass-is-greener", or a real reason to want to change.
Also, I kind of thought you were going to say something about the new Sony A7iii, lol.