I prefer to Migrate vs. Upgrade (in most cases).
I've upgraded like 20 sites from D6 to D7 of various sizes and complexities, and one thing I have learned is that most of the time things work out better when I bite the bullet and recreate the site from scratch in Drupal 7 then migrate the data from the D6 site vs. upgrading.
It doesn't take nearly as long as you think, and you will end up using a fraction of the modules you used to have, your database will be half the size of an upgraded site, you will get less puzzling random errors about unserialized data, etc. The whole site is likely to be leaner and cleaner.
Depending on the size of the site, I use manual copy/paste for the one-off content blocks and pages, but for something like 400 press nodes, or 9000 product nodes, I would use the Feeds module to batch import.
Bottom line: In Drupal 7, I build sites differently than I did in Drupal 6. I use a lot fewer complex workarounds to get things done, and I don't want to carry around all that cruft forever.