True, but you do have to not be lazy.
Lots of good comments and as has been widely noted, the main benifit is psychological
I actually did end up sitting down and putting together said spreadsheet and came to the shocking conclusion that Brutal 2 is worth +1 to hit for the die type (d12) if you assume a 50-50 chance of hitting with the axe.
If you hit on a 10, the axe is slightly better, if you need an 11, the sword is. This number moves a little depending on bonus damage, the 10/11 split was with +11 damage, at +15 damage the split happened at 8/9.
For those curious what assumptions/factors I included in the spreadsheet:
30,000 attack rolls
Best of 2 d20 rolls
Effect of Brutal 2 on both regular and High Crit damage dice
Bonus Weapon Damage
I did not factor in the effects of dice that do 2W or higher damage.
If this all seems a little excessive on the analysis, in my defense, I am a civil engineer...