I think Bountyhive is in the right track! Is quickly becoming very recognize in the bounty world.
For my experience I have no complains at all. I participate in some of the campaigns, and the ones that already finished paid well and right after ICO end.
Usually I participate in the Telegram bounties, but lately it has been quite hard. When a campaign is launched, after a couple of hours all the spots are filled. I know that the site has a bunch of user, but Im used to watch this campaigns in bitcointalk and they do not fill that quickly!!
I understand the question of the transparency. They should present spreadsheets of the participants and show what they are doing to avoid cheaters.
Also, they should have some kind of status for you to see how you are doing during the campaign. I saw some bad feedback because a few people only find out the arent eligible to the campaign when they dont receive payment.
PS: Can someone explain and give proof of those 2%??
Yes, I totally agree with you, if you meet the requirement, you will get your reward. Bountyhive, Amazix, Tokensuite is the future of bounty campaigns, because they are strict in rules and constantly update spreadsheets.