The "mentioned" feature is pretty awesome!
I'd also go with the AUG over an MP5 clone. MP5s, be they clones or the real deal, are heavy for what they are.
The Ergos are not that great:
The selector switch is very shitty awkward where it sits in relation to the pistol grip.
There is no bolt hold open so anytime you get a click instead of a bang you remove finger from trigger, lock bolt to rear, and either change magazines or tilt right and shake out brass then release the bolt then fire or go on safe.
And its heavy. If you run the collapsible stock the toe of the stock needs to be high or barely on the shoulder so that you get a good clean sight picture with irons. Running red dots mitigates it somewhat.
The MP5 is a sexy cool gun (like the P90) but just like dating a new girl, the shine quickly wears off. AUG is a much better choice.
Edit to add: The MP5 does have some positive attributes. Its very compact especially with the collapsed stock. If you can get a PDW version then it becomes an incredibly niche weapon for PSD assignments or when you need to be heavily armed yet hidden as you walk around in street clothes. The Eagle shoulder rig for it is incredible and letting you tote it under a coat or jacket. MP5 magazines are all but impervious to failure. They are steel and weigh a ton but they very rarely break. CQB with the PDW in tight spaces like aircraft or trains (think tubular assaults) is easy with the PDW but make plenty of accurate and repeat hits on your target since its a 9mm.