Robot lets rider walk and fire just like Gundam

These mechs would be much more efficient if they were smaller and sort of built around a soldier. They could be faster and as akilles said, they could have much more firepower, and much more protection.

A real mech walker would be cool but that think is crap, it just shuffles and wheels along

Very cool. But as said it would have no real military use at this time because:
Too heavy, meaning it would be too slow
Even heavier to add armour that could deflect light bullets, let alone mortars
Dangerous for the pilot
Could get ambushed from behind, meaning it needs multi-directional cover
No where toi store any sufficient amount of ammo, meaning constant stops to get reloaded

In time, we might see these somewhere in the military, but not for a few more years, too many problems that need to be fixed...