Whilst using some other new social sites I've been tracking their progress using Hypestat. I've found their stats to be fairly realistic. They use Alexa that relies on people using their extension, but the trends reflect what I see elsewhere.
At the moment Steemit is looking good. Visitors are increasing and they are engaging with the site. Views per visitor is important. Steemit does not depend on advertising, so it's not so important where visitors come from, but it's still getting a lot of users from the US and Europe. Some other sites end up with lots from southern Asia trying to cash in. I'm not sure they would do so well here due to the way it's designed. Irrelevant comments will get voted down.
I'll be keeping an eye on the stats. Of course there are other sites that give an insight into actual usage of Steemit, but it's useful to compare it with other sites.