I want have downloaded a bot (Darkbot) but i was having some problems and i stopped running it. I also have downloaded an other bot, a better one, a very good copy of eggdrop(Linux) in windows. Darkbot was good as it was able to see the replies of the chatters and reply as you were setting. But a very big bug was that it couldn't search on the post but it was editting the as they were.
Bot's are good if they can be running all day-night on a server and work as a FAQ of the channel.
For example. I was running the bot on a channel that was about the aliens called SETI@Home but who would know about this project, so i set a part of the topic of the channel:"Write HELP to learn more about this channel". Then the bot was going to reply and showing to the user a list of topic and FAQs about this project. So with this bot they could understand more about this project. It was working fine, but i don't have a server.