I have many ideas and limited time. And many of the ideas I want to work on get interrupted by pressing concerns such as bug fixing and high priority features. Because of this, I tend to have many small improvements lying around in my trunk. Then when the time comes to commit a quick bug fix, I face an 'svn status' output with lots of 'A', 'M' and '?' indicators. In short: a time sink.
But today I switched to git. I'd experimented with git before and had to get used to the new commands. But the advantages of maintaining many branches easily was always very appealing.