I was researching for primary tools to update and migrate records. It came down to Excel Connector, Salesforce's dataloader, Salesforce's core functionality itself, or Dataloader.io. Dataloader.io ended up being my last option to test, and it would have been nice if it was my first, but I need to understand the limitations of the other options. During the time I really needed to do a massive migration, Dataloader.io was the only real comfortable options I saw from my search results and had very positive reviews. Other products may end up being too risky.