The MP7A1 is still better in terms of CQB, Armor-Penetration, and Rate of Fire.
The MP7A1 has a fire rate of 950-1150 rpm depending on the ammo type.
The M16A4 has a fire rate of 750-900 rpm depending on the ammo type.
The M16 has a higher muzzle velocity, has been in service a lot longer, is better for medium-lon range fighting, and is good for adaptibility. Those are the only fields where the M16 outranks the MP7A1 and in today's battles most soldiers want a weapon that's small, effective, reliable, and powerful.