both are pearls but i think that's where the comparison ends.
doom is sanded 1000 grit dull; u-turn is highly polished.
doom's cover is/seems to be a weaker cover, than the u-turn's.
if the u-turn were sanded to 1000 grit, i believe it would be stronger than the doom. u-turn's core is similar but the shape is more flippy than the doom's.
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"...for advice is a dangerous gift, even from the wise to the wise...."
J. R. R. Tolkien