Personally, i don't use plugin for that. I did include my twitter account in feedburner. So whenever i create a new post, feedburner will automatically post my new post to my twitter account, and i have a less plugin to use
i use the plugin "wordtwit" on my site very simple to use just set it and forget it.. i havent found ne issuses with it at all
Most (if not all) plugins require a twitter API authorisation code to be created and utilised for each twitter account. This makes for a great deal of work for people with hundreds of blogs. Twitter tools suffered exactly the same when september came around this year with twitter's new api rules. People who recommend this are not thinking large scale.