Ok, my $0.02
The first thing I think when ppl say "so and so weapon is better because an army uses it" is idiot.
Ppl don't understand or can't or better yet refuse to accept army choose weapons for a) political reasons (we built it, it's better) b) economic reasons ( it's the best, look we use it you should too and buy it from us and help our economy) and c) economic reasons (ah this rifle is the best in the world, but...... the pricetag..... is 4000 a unit, this rifle is Ok, and 400 a unit. Hmmmmmm which to buy?) so keep in mind all military rifles are Ok rifles made by the lowest bidder. Otherwise we'd all be using some version of the G11.
Besides, Israel uses more m4's anyway.
Xcr was developed by RA for the so com trials and lost because, get this, not for being reliable enough, because they couldn't make enough BFA and FN is bigger and more influential then RA.
So, to compare the 2:
Tavor:
Pros:
Reliable (it'll eat anything)
Compact (yep, it was designed for urban operations)
Well balanced (yep, kind of a convient to do stuff)
Light (yep, for the weaker of you ppl)
Ambidextrous (BUT... can't shift to weak hand shooting without eat brass.....)
Cons:
Plastic ( all the metal inserts in the world won't stop cold weather from shattering plastic with hard military use, like say -35 and smashing your weapon into a Window frame on insertion)
Optics (can be a ##### to mount without a spacer and with that the bore to sight line is like 4-5 inches)
Ergonomic (yes comfortable, but... limited in what you can do with it without expensive aftermarket accessories ie rails for paq, flashlight, sight, back up sights and that #### that negates the light weight pro)
Controls ( in urban ops life and death are measured in seconds, so taking your hand off the forward grip moving back hitting the mag release the n a mag for an emergency reload, is well too long, where's you can hit a button and grab a mag for quicker mag changes with convention designs. However the design does lean a little towards being designed for gross motor skills a bit makes it easier to train a conscript army with radical new design ie fodder, unless your of the ppl who release the pistol grip and sacrifice positive weapons retention for a fine motor skill of changing mags... dummy... what if you trip over battlefield debris? a divit? A piece of grass? Your own 2 feet? Your giant gut even though your in recondo and listening to CSM (name witheld) and part of a leet unite? Your hand never comes off your pistol grip)
Accuracy ( even though it'll eat bullets no problem it suffer from a minor thing called accuracy the norm is 2-4 inches of accuracy with any given ammo, 2 inches at 100m is 4 at 2 and 6 at 3 center mass, means your barely in the target area with perfect condition, now add a muscular, extremely fit, expert shot, such as u r self and trained by an elite force such as the ISA led by colt silver, and your a force to be reckoned with. Point being, one slow hit is better then 2 fast misses)
Xcr
Pros:
Conventional (require minimal training to adapt)
Reliable (eat'll eat most reliably and has adjustable gas to further enhance)
Accurate (the norm is 1-2 inches)
Modular (you can add whatever #### you want to it to make yourself look like whatever chair borne commando you want)
Design (conventional as stated above but a mixture of common battle designed kind of what you'd get if an ar mated with an Ak and something popped that looked like a fal. Meaning it familiar to take apart and clean and maintain with minimal training and tools, not that the tavor is hard to learn)
Cons:
Heavy (hit the gym more, you need it)
Some QC issues ( like most car brands to, and constantly evolving because Alex reads these forums... and takes that into consideration as he evolves the design to be better, which I don't mind and prefer if it gonna make a better weapon that someone may have to rely on in the future and if my feedback helps save that person life.....)
Custom service ( Ok, but I agree with Alex, you want service, tell us what the problem is and we'll fix it ASAP, after the 40 ppl in front of you, you scream and rant about how awful the weapon is and how big a piece of #### it is and that my customer service is a giant $#?@, well sir, well get to you when we can, have a nice day.) I agree, who cares who you are 1000 years from now, no one well and your existence won't matter.
But to use "no army uses it" shows a) your level of understanding about the world and b) your level of maturity
And no weapon is perfect, including the ar, it all personal preference when you have a choice.
PS. I'm on my phone hence the #### layout and grammer.