Some say responsive web is a must to make your website look its absolute best on any platform. I say it's your best bet to keep your web visitors from saying "Ughh" when your boxs don't algin in their screen.
You must adapt to survive, without adapting you will get left behind and web visitors will go somewhere else somewhere more visually appealing and user friendly
Whether you use a 4" iphone4 or an 8" samsung galaxy tab or your playing around on your computer each website you visit must to adapt