I had made a first article on bots, briefly comparing the different existing styles.
That you can find on this link
https://steemit.com/fr/@alex.frouge/le-bot-est-il-notre-ami
In this article I explained that the profitability passed by a coefficient multiplier above 2.25, below you will be losing.
I categorized the bots into three families.
Bid bot or bid bot
Promotion bots
Manual bots
The bid bot
The bots of auction do not guarantee a real gain, you will be in the end very often losing. These are bots that take time to properly place your bids. But despite all the precautions taken, you will end up with a lower upvote than what you sent (counting of course the upvote at -25% curation and / 2).
Promotion bots
They allow you an upvote between 2.25 and 2.60 on average, so remain interesting.
@randowhale
allows sending only 1sdb, but is often dormant. It is necessary to supervise on the site steembottracker.com the moments where you can use it. Interesting when available.
allows various consignments in SDB or STEEM
It is necessary to look on the site smartsteem.com the maximum upvote of the possible moment in simple user.
A white list exists in addition, allowing you to be upvoted by members who have chosen to vote only verified users.
All requests for upvote do not always happen, you have to try again several times. Favor several shipments to a more consequent.
For example, do not send 1 sdb but rather 4x0.25 or 2x0.5
@minnowbooster
send a sum in SDB or steem for an upvote.
As @smartsteem favor split mail to have more chance to receive upvotes.
Manual bots
@ Friends-bot
Limited to shipments of 0.010 or 0.020 sdb or steem.
The upvote will be guaranteed in x3 (more interesting than the promotion bots), so no loss possible.
The upvotes are still low 0.030 for 0.010 sent, and 0.060 for 0.020 sent.
If this bot stays in X3 when it has more VP, it will be very interesting. It also offers a restem service for 0.20 sdb or steem.
Few sometimes end up sleeping to recharge his VP.
Conclusion:
I can only advise you to use the manual bot which to my taste remains a safe bet.
Avoid bid bot that often only enrich their creators.
Try the promotion bots that remain interesting despite their lower rates than the manual bots.
I would try other manual bots in a short time. In order to compare their seriousness.
Source photo: http://botstar.net