MSTest hasn't changed much since it was originally introduced, so those old comparison posts are still valid. Microsoft's focus on ALM is mostly targeted at further tooling and server products, but the fundamental testing framework hasn't changed much.
It's also worth noticing that MSTest and their entire ALM strategy is targeted at many different styles of automated testing, including Integration Testing, System Testing, Performance Testing, etc., so while it attempts to be a one-size-fits-all, it's quite ill-suited for unit testing, because it's too heavy to work with.
While NUnit is better, I wouldn't recommend it either. It, too, hasn't changed much for years, and the extensibility model is frankly a mess.
Instead, I'd recommend xUnit.net. Although it's not perfect either, it's currently the best mainstream alternative on .NET. There are many reasons why xUnit.net is better than MSTest.