I've noticed that the new map viewer always seems to run choppy on my computer. Looking at the windows task manager performance I can see panning slightly will spike the CPU for chrome from ~0% for that window when not moving up to 80% CPU usage by chrome (100% overall). Panning the old map viewer the chrome window only uses about 15-25% CPU.
On a different computer, it ran fine, but the task manager was showing GPU usage. So it turns out my chrome browser setting had toggled off "Enable Hardware Acceleration". Turned it back on, relaunched and the new map is now buttery smooth.
That is a relief so I thought it might be helpful to post if others are having the same problem.
