Safari runs smoother because afaik, it's the only browser that has the NitroJS engine, which is Apple-proprietary. Chrome and Firefox don't have it.
But when it comes to HTML5 sites, Safari doesn't do a really good job, so I use Firefox for this.
Chrome is Google and anything Google that you use will be sent back to Google for them to target ads at you.
Google is also in bed with the NSA. Sure, some of their engineers issued a big '**** you' message to the NSA, but I don't buy the story, because it's the management that's in bed with the NSA. All their statements about 'protecting privacy' is all PR bulls**t.