My experience with 2017 has been the polar opposite. It runs glacially slow compared to the 2013 installation on the same machine. The startup time makes eclipse look lean and mean, it takes over a minute to start.
Weird... It takes less time to start up for me, and compiling .NET Core is quicker, it even told me ReSharper is slowing down startup time at one point and suggested I disable it. Also suggested I disabled another component on startup because it was taking longer to start VS as a result. I guess it may vary depending on system specs? Not sure. I run it both on my workstation at work and on a VM on my laptop and at my home desktop.