Hopefully it’s different if you explicitly say “vote for helpful reviews, not just reviews that you agree with”, or if you have one button for “I agree with this review” and a different button for “This review was helpful for my assessment of the post” (and it’s possible to select both buttons).
I’m a bit worried that if you let users vote on reviews, you’ll mostly get something identical to karma.
Hopefully it’s different if you explicitly say “vote for helpful reviews, not just reviews that you agree with”, or if you have one button for “I agree with this review” and a different button for “This review was helpful for my assessment of the post” (and it’s possible to select both buttons).