Some horses are mudders - they run well only when the track is wet. Some are good on short courses. Some can jump. Some can run long races. Some understand dressage. The quality of a horse depends on what you're trying to do with it.
Another way of saying, "Let the application dictate the architecture". A wise engineer I know (until he was laid off last year) often uttered this phrase.--ScottJohnson
And let the AcceptanceTests dictate the application, so you can really tell which qualities your horse needs and which ones are superfluous.
A doctrine for determining which platform, language, or application is best suited for the job. "Which one is better... Windows or Linux? Java or C#? FaceBook or MySpace? Horses for Courses." --MichaelLeachA Horse for You
We have fast horses for folks who like to ride fast.
We have slow horses for folks who like to ride slow.
We have big horses for big folks.
We have little horses for little folks.
And for the folks who have never ridden before,
we've got horses that have never been ridden before.