I think it is but many disagree. (many agree too

)
For going to europe zone 1, it has great value. Especially if comparing it to AAdvantage.
BA 1.25 miles per $1 spent
AA 1 mile per $1 spent
the higher taxes are more than balanced out by having to use half the amount of miles in J or 40% less in F. Then again, as mentioned above you earn 25% more quickly with BA.
yes, booking LAN for south america is a great deal but who said you can't do both