His side finally recorded a victory over the Irish having lost on seven consecutive previous occasions.
A hat-trick from Andrew Henderson and tries from Ally Hogg and Euan Murray secured a 31-21 success over the Triple Crown champions in the World Cup warm-up match.
Hadden fielded virtually a full-strength side but there were a couple of changes from the line-up he preferred in the 2007 Six Nations with the World Cup next month in mind.
The most high profile and interesting was positional; Chris Paterson being moved from the key man in the back three to his favoured stand-off role.
Hadden was pleased with the former Edinburgh utility back's performance and hinted it may be something he perseveres with in September's tournament.
The former Edinburgh coach said: "I think Chris gave exactly what you would expect from Chris.
"He's a very talented footballer and he made one excellent half break while his handling was pretty good in difficult conditions
"We need to look in a bit more detail as we always do to evaluate how different players performed because it's a difficult thing to do straight away.
"We'll look at how the different pairings went for is and how the units went and take things from there."
Hadden was also impressed with the way Rory Lamont responded to a rare start at full-back in place of Hugo Southwell.
Lamont, played mainly on the wing in his occasional international appearances to date, demonstrated a willingness to counter-attack as well as a strong character.
Hadden said: "It wasn't necessarily a day to assess the backs all that well because of the wet ball but we'll see enough when we look at the tape to see if we had the right combinations.
"I was delighted with Rory though. He had a shaky decision early on but the fact he recovered from that was quite impressive and he definitely came out on the plus side, there's no doubt about that."
A return to the fold of inspirational captain Jason White, out with a knee injury since November, was another bonus for Hadden.
The Sale flanker suggested he will soon be the force of old with an encouraging display as part of a terrific effort from the forwards, not least from all-action young hooker Ross Ford.