I won't read replies about the safety of Round-up because it just gets me riled up, so I'm going to put in my opinion for no Round-up. Pardon if what I say has already been mentioned, I simply cannot get tied up in casual debate about this.
There are other ingredients not required to be listed that are controversial, and the main ingredient's "safety" has been recently been put back under the spotlight.
But here's the honest truth: there is no such thing as a permanent weed solution. Weed seeds happen. They are in the air, on the feet of birds, in the fur of animals, in poop deposited under trees, carried on the undercarriages of cars, on people's clothes. Some seeds can sit latent in the ground for decades. Grass runners creep in from lawns of your own and your neighbors. There isn't anything you can do once that will eliminate all your weed "problems" once and for all.
Second truth: replacing your current idea of what's a problem and what isn't is one of the best things you can do for yourself. For me in regards to, say, my lawn, if it's soft, it's good in the lawn. If the chickens can eat it, it's welcome in the garden beds... for a while (I love dandelions!) If the plant, shrub, tree I want is not overwhelmed, then I don't particularly care. *Poof!* "Problem" gone. Permanently. No Round-up required.