Better from whose perspective? :)
The machines can potentially be more durable, and also scalable. We are fragile, we don't scale very well (though trying hard through globalization). Today we can't even backup/restore a person's mind. In fact I think self-aware intelligent machines will appear sooner than the technology to backup our own biological brains.
They will scale their brains, they will expand their "natural habitat" towards other planets, solar systems and even galaxies, like those all-eating self-replicating automatons. Easily.
So while we are at it, looking at the grand scale of things, just one question: where are all these machine civilizations in the Universe? Why aren't there any traces of exponentially growing all-consuming machine civilizations anywhere?