Sorry about that. We do need to improve the UI perf. Can you try it with the minimap off and let me know if it's faster? There is a "secret" way to disable the minimap: (1) hit Cmd-Shift-P or F1, (2) go to "Preferences: Open User Settings", (3) search for the "editor.minimap.enabled" setting, (4) hover over it and press the pencil and select "false". Then go back to the file and it should not display anymore in your current browser.