Pros:

• Reusable
• They’ll never water down your drink.

Cons:

• which DOES have it’s own distinct taste.
• There’s also the matter of the cubes breaking open and getting nontoxic goo (it’s not dangerous, but it’s still disgusting) all in your drink.
• Then again, I don’t see any seams on the cubes, or even know how they get the gel in there in the first place, so I very well can’t assume that they’d burst.