The weight may be the same, but the air incorporated into the WOTA's spinning process does not weigh anything. It might be worth a gauge swatch, because you really can't tell just looking at a yarn if doubling will equal something else. Here's a picture of the two. This is what I mean about the fluffiness of WOTA.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry