As mentioned by the others here, there are too many factors that play into the speed of a migration. The bandwidth is definitely a big one, especially going to Office 365 since we have no control over the server itself.
Then you have the amount of properties and of course the number of versions in the version history.
Many did not realize that having 10 versions of a 10MB document is actually 100MB (estimate). This means transferring all of that information with the right properties over.
Most tools will migrate at fairly the same speed when going to Office 365, you should simply look at the the one that works best for you whichever it is. I am a little biased too as Gemma is, as I work for Sharegate http://en.share-gate.com. And if you have time, we created some funny videos worth checking out completely unrelated to migration :P http://en.share-gate.com/funny
..And my super awesome powers just noticed the date on the post haha