The training school environment is nothing like how it is on the street. Play the game, pass the modules and the real education begins once you're out.
Greeting everyone with "sir" or "ma'am", makes you come across as a prick.
OST maouevers appear great on paper, but by the time you whip out your baton, extend it and work out which way to insert it to perform a reverse arm bar then you've been lamped by your suspect.
Bulling your boots makes you stand out like a sore thumb to any self-respecting service user.
In the training scenarios, you've got a complaint detained, plenty of back-up at the touch of a button, a cooperative witness and the dude has been found with a bag labelled "swag". In reality, they're kicking off, witness is calling you a piggy bastard, the nearest sets are miles away stopping a car and the sergeant is temping and useless.
Uniform standards are difficult to maintain. The scuffs you get from a roll-around and wear & tear accumulate like fuck.
Statement taking from normal MoPs can be easy; Statement taking from someone coming off their methadone (disclaimer- other prescribed meds are available) is somewhat less.
Plus, these fuckers lie. Like, "I'm clean now, officer. Drugs are bad," as they've got a kinder egg inserted causing them all sorts of confusing emotions.