My mom has one and loves it. You can get whatever you want for coffee (and cocoa, and tea) in terms of flavors or caf or decaf, and it's always fresh. It does get expensive to keep buying the pods, though.
I like using it when I visit her. However, my personal issue is that it is not "green". There is a good deal of waste every time you brew a cup of coffee, and I don't think the pods are recyclable. Also, the pods are packaged in a larger box (which is recyclable, being cardboard) but again, to me, lots of waste. We compost, and so we are able to compost our coffee filter and the coffee grounds. For me, the Keurig wouldn't be an option since we try to make "green" choices where possible.
So, if your recipient is of a similar mindset, h/she might not enjoy that part of it.
Not trying to be a "downer" - but just wanted to mention it.:-)