I've been using Firefox and Chrome, and am not happy with either. Firefox used to be my preferred browser, but in the past yeatrs it became a memory hog. As for Chrome, while it uses a separate process for each tab, it doesn't seemt to use as much memory as Firefox. But that greatly depends on the sites I visit.
That said, I've switched off everything I can in my OS and browser settings to prevent data mining of any kind - and that does include quite a few obscure things that you can only find when duck-duck-go-ing for it (you didn't expect I would be 'googling' for it, did you?). In the end, I can say that while I do get my share of targeted advertising, my system and browser experience is pretty much clear of obscure processes, data being sent behind my back, or stuff being sent to me without asking. SPAM in my inbox (spam folder, actually) does never reference any online identity I use - they're only mass mails, and that makes them easy to recognize, and managable.
So, independently of the browser you use, if you are always careful not to give out any more information on the web than is absolutely neccessary, and spend some effort to make your system and browsers behave, you can be relatively safe.