One way to speed up glass is what the refraction index is set to. As the material setting gets higher toward crystal and diamond it's going to slow down much much more. To speed it up more try setting it closer to 1 but not one but try setting it lower that you got there. Lower than even normal glass if it's solid.One more way is avoid solid glass and make it a bubble shape instead with Boolean difference. A smaller sphere within a bigger sphere. That will also speed it up. Grouping propeerly helps lots too. Just do a search for grouping on this forum for posts by me. I've explained it lots of times already how to do it for maximum render speed. The computer speed has lots to do with it also. Slow computers take longer of course than faster computers. If you have a fast computer than your doing it wrong. Look above for it's solution, it works. You can probibly cut it down to 5 hours or less if you tweek the scene a bit. One other thing too if you don't need absolute perfection Broadcast quality gives usually excellent results. Like there is no use waiting 11 hours for something to render then converting the picture to jpg format. It's counter productive. The resulting jpg image is worse than a broadcast render.