One thing that Git and the other DVCS's massively improved over Subversion is that commits are local, and you only need to talk to a remote endpoint when you push/pull. In Subversion, every commit would require uploading changes to the repository server, which encouraged larger commits (to amortize the overhead).
Yeah, this was huge at the time. Laptops were good but Wifi wasn't as ubiquitous. If you wanted to work on some code while you were traveling or at a cafe or something, you'd at best be working without version control, making ".backup" files and directories and stuff. With DVCSes you could branch, commit, etc. as much as you wanted, then sync up when you got back somewhere with good internet.
