I've got most of my reviews accepted by the site. They prefer very straightforward reviews even if you curse and swear (ok, i am joking) meaning they like your review even if it is very one-sided and just bashing. They don't like "professional" reviews that does more description and trys to stay neutral or nice.
I am saying this from my experience, i started out writing more in a neutral way too and they don't like it.
However, all my reviews are given bulk rates. I am not saying i deserve the full rate but I can't help but feel they don't ever pay the full rate, especially not with their preference. And their payout is very high, outrageously high that you have to write more than 50 reviews to hit it.
So you'd have wasted a lot of time and efforts before knowing if you can get paid.