Chrome is pretty tough for Glitch because they constantly update to pre-release versions of Flash and break things so you have to be a bit more on your toes — not saying you shouldn't use Chrome, but it does have drawbacks for Glitch. Safari, Firefox and many other browsers are all good.
But, the number one tip for the best experience: whatever browser you use for normal everyday stuff, use something else for Glitch — when Glitch has to compete for Flash and general browser resources with every tab you have open both Glitch and everything else will be slow. When it doesn't .... way faster and smoother!