By dimensions, assuming the 2015 ("eleven year old") version, the 13" M4 MBA is 0.17" wider, 0.9" deeper, and 0.32 lbs heavier. Where it's harder to compare is thickness. The M4 is 0.44" thick where the Intel one was tapered (0.11"-0.68").

Kind of hard to see that as "HUGE" in comparison. Bigger? Yes, but not really huge.