I was a big Seesmic fan , tried going back to HTC Peep just to cut back on the number of apps I had downloaded... but can't commit.
Tweetcaster was nice , liked it on my BB Curve, but it takes forever to load so that was a sure fire way of getting deleted off my phone.
Tried using Twidoroid several times, just because it seemed to be "the" one .. but never seemed to dig it completely.
I first downloaded Touiteur after I purchased BW's ... but it was really slow. Loved the layout but it seemed to take forever.
After reinstaling it some time later, it seemed to work faster and is my only Twitter app (besides htc peep...) that is installed.
Until Social Scope transfers my BB account to Android....