I am looking for a Linux OS to boot into just to do web browsing, as it is so much faster. I don't want to partition though. How bad is Wubi? Will it still be faster than Windows 7 if it is installed this way?

I've recently installed Ubuntu 12 for somebody through wubi and everything seems perfectly fine. Well, except for the Unity desktop interface, but that ain't wubi's fault.

Besides OS faults, does it still run fast? I heard it runs slow, and no better than Windows. I just want a fast OS to boot into for casual use, leaving the more bloated Windows 7 for specialised software usage like Microsoft Office and Photoshop. Partitioning isn't worth the effort, but Wubi sounds interesting.