Strands of Astral Power. Worth it?

[Dedas]

Tuidjy said:
It is drain 2, but what does it matter? As if +2 or +3 to penetration would
make a difference. I have no SCs at under 22, and no mage under 20... I doubt my
opponents do. So instead of MR 23, they would be MR 20 if I had magic + 3. Woo!
Then I'd have made a killing... Unless there is a way to reduce the enemies' MR
beyond the measily +2 from magic 3, this spell is worthless.

Oh, and when I said 30 mages, I lied. In just one province, there's about 50
astral mages... and not one was detected.

Nope, he says he has drain 2.