You called it when you highlighted Jason Statham. He is so good at taking the mickey out of himself!
The guy is a laugh riot. Not only did did his character sever his arm and reattach it to the other arm, but he also used a raincoat as a parachute and he once successfully impersonated Barack Obama, giving testimony in front of Congress. Statham is so wired, a blunderbuss crashing through the plot like James Bond and Mr. Bean rolled into one.
This is also Melissa McCarthy's best movie, because it's so damn funny, its got non -stop Bond style action, parody of that action, Peter Sarafinowicz as a groper and McCarthy doing her loveable inept-shtick-before-rising-to-the-occasion routine to perfection.
I normally wouldn't say this, but as long as Jason Statham reprises his role, I hope there's a sequel! :)