Bruce attempted to bring the Republic of Ireland striker to the KC Stadium in a failed deadline day move in September but succeeded at the second attempt last month.
He gambled £6.5million on a player who might have been out of contract in the summer, but saw his first returns when Long scored 12 minutes into his home debut against Tottenham on Saturday.
It was Hull's first goal of the year and afterwards Bruce was beaming about his acquisition's qualities on and off the field.
"He's a delight," said Bruce. "A lot of times with professional footballers in the limelight, their misbehaviour at times makes us all cringe.
"But he's one of them we know for a fact lives his life properly, works hard and wants to play football.
"We've been chasing him for the best part of six months, so for him to score after 12 minutes (of his home debut) was fantastic.
"He'll be a great addition, no question at all, because I've seen him over the years scoring goals like that.
"But it's not just that, it's his attitude towards the game."
Long showed signs of a productive partnership with another newcomer, £7million man Nikica Jelavic, and Bruce hopes they can score the goals to keep Hull in the division.
"I thought to myself at times against Spurs, 'I wouldn't want to be playing against those two'," he said.
"We're hoping they can (become prolific), that's the plan. That's the reason I knocked the chairman's door.
"We've added to the squad and brought in an extra bit of quality. No disrespect to the ones we had before but these two are far, far different to what we've had."