Does more megapixels always equal 'better'?
Only if all other factors are equal. More sampling sites allow you to print larger from captures of distant subjects with fine detail. Fewer sampling sites of equal quality and more focal length can achieve identical results in many cases.
When the "quality" of two samples is equal in all other respects, and one sample has more electronic resolution, then you can simply make larger prints of subjects containing fine detail because interpolation algorithms have real data to work with.
The "quantity" of sampling sites is less important for close-up or macro work than for distant landscapes, etc., at infinity focus. If your use leans toward landscapes and you intend to make larger prints, then more is usually better. Otherwise, you may get excellent results from much less resolution. A case in point would be the excellent photos from the Olympus E-100RS and C2100UZ with the 10X stabilized zoom. These images are often equal or in some cases superior to crops from 5 megapixel captures simply because the optical zoom has more than compensated for the sampling differences.