So I began to take note each time I experienced a little hit of outrage or condescension or envy during a Twitter session. What I found was that nearly every time I felt one of these negative emotions, it was triggered by a retweet.
I've been noting my reactions to tweets and found the same thing - that retweets are the single most toxic component of my current Twitter feed. I will use whichever Twitter client allows me to completely disable retweets. Some, like Twitterrific let me disable retweets for individual users, but not for everyone all at once. Lifehacker posted a script for doing this on twitter.com but it doesn't work for quoted tweets and I'd have to remember to rerun it each time I follow someone new. It might be worth a try while I wait.