K-cups are definitely a convenience factor in my mind. Just like Nepresso, or Illy Capsules. K-cup machines are made from non fixable parts, and once they go out (which is often enough) they have to be fully replaced instead of just replacing a simple valve or capacitor, the cups themselves are not environmentally friendly, as it adds significantly to the waste pool - another thing to keep in mind. Though, yes you can use the reusable K-cups, I'd point you back to the start where I discussed the fact that the machines are not fixable.
French Press, IMO, tastes better and can be brewed to your particular desire of strength. There's a reason that the best coffees in the world recommend and suggest the use of a French Press for extraction. It just does it better. . .
NOW, I will say, My wife does not like the French press as much. Dirty, gritty some times, and stronger. . . and she doesn't always want to turn on our espresso machine to make espresso, so I got her a coffee pot, and I have to say, this unit makes the best cup of coffee I've had in comparison to other units / k-cups / drip filters. It's a Mr. Coffee, and runs around 60 bucks at Walmart. . . for what its worth.
I tried to find the article, that I believe appeared on VICE, or one of my science daily pages discussing the Keurig and how its "cheaply made" to break over time. But I can't seem to locate it.
But as a true coffee fan, and someone who tries to be eco and budget conscious - I would avoid!