I like this analogy.

I think of a bike's shifting systems; better shifters, better housings, better derailleur, or better chainrings/cogs can each 'improve' things.

I suppose where that becomes relevant to here, is that you can have very fancy parts on various ends but if there's a piece in the middle that's wrong you're still gonna get shit results.

You only as strong as the weakest link.

Your SCSI devices are only as fast as the slowest device in the chain.

I don't need to be faster than the bear, I only have to be faster than you.