You can probably ask the same question about taking insurance. If you know that the deck is rich should you take the suckers bet? Personally, I always stick to Basic.
I always stick to the BS. But the other night I was playing and the count was +3, dealer shows an ace, and I take the insurance. Dealer has BJ, so I did the right thing! (I was dealt a 20.) I know that taking insurance/even money is the #1 play index the Illustrious 18. As I mentioned in my original post, for the very next hand the count dropped to below +3, so when the dealer had another ace, I didn't take the insurance, and lost when he showed a 2nd straight BJ. And the count dropped even lower, so I didn't take insurance when the dealer dealt himself a third consecutive BJ! Oh well, them's the breaks. . .
A2 v 5 is another one, double in positive counts hit in negative counts. A8 v 6 is a basic strategy double but you should double A8 v 5 at +1.