First, call everyone "sir" - better results.
If at Red Flag and you hear:
"You guys did a Good job Out there" - means brit average
"You guys did a great job" - above average
They don`t have a word for crap as in the US-of-A-world of how one is perceived, this is one that can`t be lived down in the bar.
Excellent is "outstanding" and is reserved for people at dining-outs or day-to-day reference to George Bush