Certain sites' insistence on displaying the mobile version even though I've set the browser to be in desktop mode has made me install Firefox for viewing those sites specifically.
The stock browser on the 4G LTE is pretty impressive, especially when you're using mobile Flash. I'm only using the Chrome beta when I want a tab I know I have open on one of my desktop/laptop computers. The stock browser seems to be much faster than Chrome for me, and the stock browser gets all my bookmarks from my Google account which is nice.
Firefox for the win. No tracking, no ads slowing you down, built in password and bookmarks sync, and much faster tab access than the stock browser, just swype right and there they all are. So good.
Chrome beta. I hate that the stock browser doesn't open the YouTube app when clicking YouTube videos or links. The multitasking on chrome is amazing as well. Loving how simple it is to switch between tabs and I personally prefer the look and feel of chrome over the stock browser.