I've seen cable used (on the deck that our architect built at his own house), and it looks nice - unobtrusive, kind of industrial chic. His deck was grey Trex, with (I think) aluminum or steel posts, so it blended in well.

We opted not to use cable on our own deck for a couple reasons:

- The tension on the cables (to keep them taught) would have required substantially beefed-up posts, and would have put a lot of strain on the posts at corners, where the cables would have to make 90-degree turns. Given that we wanted to use ipe posts, rather than metal, it just wasn't practical to engineer them to take the strain of the cables - especially since the wood itself wants to move somewhat. We would have had to keep adjusting the turnbuckles to accommodate the movement of the wood, at least until it acclimated and stopped moving.

- The cables are horizontal, which, with small kids in the house, makes a perfect climbing ladder, right over the top of the railing. Not a good idea for us.

We opted not to use glass for exactly the reason you cited: we didn't need to spend the rest of our lives with a bottle of Windex in our hands. It wouldn't be just sprinklers and birds for us, but toddler hands and dog noses too.

You should consult your local building codes before deciding on a cable railing. They do look cool but because of the climbing issue mentioned above they are often not allowed.