Speed is NEVER the mark of a good browser. It can be a point on a list but, if it fails to properly implement standards or work in all devices, that's a failed browser. It's not the whole picture.

But you say you agree with my point.

If your Surface 3 can't handle the computing needs of a browser, that's not a resounding recommendation for owning a Surface.

As far as developing for the web, I've own a web dev company for 10 years and, among our list of clients, we manage two web sites you have visited before, one of which you probably visit every week or so. I was also, once, invited to work at Mozilla but declined. Does that answer your question?