I use a netbook 95% of the time, so screen realestate is in short supply. I have been looking for a twitter client that meets my needs, and so far, these are my experiences.
Twhirl - liked it, until it stopped working. Like the read/unread status. Like that it doesnt push tweets off the end of the screen. Dislike: lack of being able to follow a conversation back, to see what people were replying to. Dislike: Lack of groups
status: still installed, in case.
Twitterfox - liked it, but after starting to follow more people and following more people, became harder to use.
status: still installed for busy days
DestroyTwitter - loved it, until it started dropping tweets. LOVE being able to see what people are replying to. LOVE exclusion of terms. LOVE groups.
status: still installed, pending uninstallation
TweetDeck - too big for lappy. cant change font size, cant change size of tweet boxes.
status: immediately uninstalled
Seismic Desktop - too big. No need for the side panels that take up SO much room, no need for the boarders either, that do NOTHING.
status: immediately uninstalled with cry of triumph when it was gone.
Trillian Astra - good LORD no. hard to manage, hard to read, hard to configure.
status: immediately disabled
Gonna try twhirl again - hoping it doesnt stop working <3