The M4 is 6.43 pounds empty, probably a pound more with that extra 2 inches in civilian legal trim.

The Tavor is 7.9 pounds empty.

If stock was all we had to work with then I'd choose M4 all day long 24/7. However once duty gear gets added we're putting on weight. With the M4 that makes the front and mid heavy and the rear light. However it has superior ergonomics. But you're still getting fatigued regardless. Now with the Tavor most of the weight is in the rear with the front super quick to go from either the low or high ready and not be as fatigued as one would with a hooked up M4. Adding a few things to the front like a foregrip makes it ergonomic enough for me and having the red dot in the mid like one would with an AR makes it far more maneuverable with.

Going from primary to secondary while slung with the M4 and still be stable has been a pain to get things right with. With the Tavor, it's super easy to do and I can wear the Tavor slung all day new style and be happy as a clam.

I like it. But it may not be for you by the sounds of it. No offense.