In terms of bid bots they are becoming less and less popular and profitable, with alot of them now barely even break even. Alot of them are 'reliable' in the fact that they will upvote your post if you send them some SBD/STEEM and not rip you off. I have used Minnowbooster, Smartsteem, Sneakyninja, The Rising and more in the past without any issues.
However, as time goes on it seems to be that more and more people are delegating to community bots or bots that arent just about buying upvotes.
I specifically have delegated to the Steem-UA bot where it offers upvotes based on you Steem-UA score - which is calculated by user engagement and thus encourages accounts to grow.
I also have a few Steembasicincome shares now - we can sponsor other users with 'shares' and we also get shares ourself. Each share gives us an increase in upvote value on our posts from Steembasicincome