My non restricted ACR is under 10 pounds. I think it was 9.6 pounds with my Leopold 3-9×40 in PEPR with magpul flip up sights and magpul MOE front grip.
Standing freehand in the bush it's mostly shooter error but for me I want to know it's me missing not the rifle.
In motocross it's 95% rider 5% bike, but we mod the bike anyway so we can make the most of the 5%. Same with rifles, I want the best I can afford so I can't blame the equipment, when I miss it's me.
Not many XCR's are consistent 2 moa rifles, try more like 3 moa on a good day. The guys with newer ones claim they are better but I have yet to see a picture of a target with 5 rounds sub 2 moa without other holes all over the place. Look more like best 5 out of 10 is 2 moa. They are plenty accurate enough for every day shooting and will hit a coyote at a couple hundred yards, the ACR is just more accurate. If accuracy is important to you and you don't mind spending some more money then the ACR is a better rifle.
As for the XCR vs Tavor, I think the Tavor is a better built rifle, they are very similar in the accuracy department, the XCR is a little more customizable and can be adjusted to fit a wider range of shooters but it really just comes down to which one each person likes better. If you like bullpups and want a compact non restricted then the Tavor is your choice, if you like a more traditional rifle with multi caliber options and less polymer then the XCR is a better choice.
Unfortunately the caliber choices available for the XCR are either 6.8SPC which is expensive to shoot if you're not a reloader or the outdated, dirty, and generally crappy (in my opinion) 7.62×39.
I've owned or at least shot pretty much every black rifle we can have in Canada and my ACR is my favorite. Having said that, if the AR was non restricted I wouldn't own anything else. I already have 4 of them and was up to 6 not long ago. I could have 2 good AR's for the price of one of these other black rifles that don't do anything better than an AR other than they can be used away from the range.