Intel+nVidia is no worse than AMD+ATI (which is really AMD+AMD anymore). With something as simple as word-processing, I would challenge you to notice ANY difference between an AMD and an Intel CPU. Word processing does not tax a CPU in the least.
I was an AMD+ATI fan for a long while because I always felt like they were cheaper, although nowdays they're pretty even. My current desktop and laptop have nVidia cards, and both work well -- no complaints.
Also, as much of an AMD fan as I am, not even I can deny that Intel owns the high-performance end of the CPU spectrum. Their Core architecture is top-of-the-line, and their i-series chips (i3/i5/i7) are the cream of the crop.
As far as gaming, if you look up some gaming benchmarks, it all depends on the type of game being tested. Some run better on AMD CPUs, and others run better on Intels.