It comes down to preference at the end of the day.
Single and twins can both be laggy and responsive. Just depends what you want to achieve from the motor.
Its a neverending argument
Main factors for the choice are:
Cost
Power level
And intended use.
Most of the time people just bolt turbos on just to see what power the engine can make and put no real thought or research into it. Then complain on a forum about why the engine is laggy or why they did not make their 'target' power goal.
On another note, we should get all these 400kw cars together for a cruise. Tony and Steve im talking to you