I was having a conversation with a friend about some of the bidbots and my friend was surprised at some of the features that the bid bots have.
I wanted to provide a Table of the symbols that had a quick explanation and also lists of the bidbots with some of the info quickly charted for you.
Guarantee: I have not done enough reviews to be able to say whether or not this guarantee means anything. As I do more reviews I will pop back in and drop comments below updating this.
Auto-Refund: The auto-refund may be delayed for hours if you use 
STEEM: Please note the min bid of STEEM is sometimes greater than SBD. 
Comments: If you send a comment upvote request to a bot that can not upvote comments 1 of 3 things will happen.
1. The bot will Auto-refund with a note saying we can't do this
2. The bot will upvote the post instead of the comment.
3. The bot will keep your $ as a donation.
Pre-vote: This can be an either or thing.
1. Pre-votes more than .01 add to your overall post worth so this is a plus.
2. Pre-votes could cost you curation rewards as more people pile on before the bot
3. Pre-votes at .01 or less add to the vote count which helps to get your post towards hot or trending
I have made 2 tables that list all of the bid-bots that are currently on the auction site
Bot prices are listed in SBD on the top in black and STEEM on the bottom in blue.
My experience at the time of writing this is that the bots listed as unknown are 6th day bots, that could change at any point so unless you use them frequently put your bid in before 4 mins is up in case they auto-refund and you want to add a different post.
I will be doing a separate post on how to use a comment bot in the near future in case you want to upvote someone's comment and not the whole post.
I do bot reviews under the tag #royalbotreview in case you want to read more about an individual bid bot.