Does Muscle Size Matter?

(Reclaimed from Bubblews. Technically I suppose we shouldn't discuss arm and shoulder muscles here, since they are body parts, but I doubt that anybody will complain...)

Do bulky muscles (like the arm muscles displayed here, contributed by the user known as Click at Morguefile.com) really matter? 

Some readers might prefer to consider this question from a feminist point of view: Are men's heavier muscles all that much stronger than women's lighter ones? 

Older women readers may remember a time when some of us, and our elders, actually worried that exercise might cause us to grow arms like that of the guy shown above. That question has now been thoroughly explored. Regular and intense exercise will give us well defined muscles, like the ones of which Mrs. Obama is justifiably proud, but they'll still be the small, thin, wiry sort of muscles. 

Other readers might consider the question from the point of view of men's health: Given that efforts to "bulk up" certainly cost some young men a lot of money, may be harmful to their long-term health, and may or may not impress anybody, should men try to grow bigger muscles? Or should they just focus on building strength and coordination?

I'm biased, because my father was a tall, broad-shouldered, yet wiry polio survivor who exercised for strength, and one of his cousins was "Big Ed," even taller, broader-shouldered, naturally beefy, and less obsessed with building and maintaining strength...and Dad could work Big Ed into the ground any day. 

Then for those who want to be totally frivolous about the matter, there's the guy-watching point of view: Do you consistently prefer beefy guys, or wiry guys? Quarterbacks, or tackles? Richard Petty, or Dale Earnhardt? 

I've always preferred the wiry body type. I did date one beefy guy, in my twenties. His idea, not mine, and the relationship didn't work out. Since then I've probably alienated other muscle-bound men by being seen with slim ones.

Some women do prefer thicker body shapes, I'm told. Cool. The species thrives on biodiversity.