The SAE updated their guidelines on vehicle testing sometime in 2005.
The purpose was to standardize the procedures to produce more reliable and repeatable results, and also to make sure consumers were comparing apples to apples across different manufacturers.
You'll notice that some vehicles whose generations spanned the 2006-2007 model years ended up with lower numbers despite carrying a relatively unchanged drivetrain.
So, if the 2007+ models were to be tested with the outdated standards, it's possible that they could have published the same numbers as the 2006 models. Or more, who knows.
Personally, I wouldn't sweat a measly 10hp and 4 lb-ft of torque at the crank.
How fast a car is depends on a lot of factors...and there are many variables in a14-year-old car which can render old magazine reviews pretty useless.
I've owned a lot of M45s, I still chose to keep my 08.