Personally (and this is just me) I would go for the CT100. I had mine in a small living room and was very impressed with it. Now if you had a huge living room or bedroom, I would probably go for the CT500. They both sound great and the CT500 is definitely a considerable upgrade from the CT100. CT100 sounds amazing (especially for the price) in a small bedroom though.
Personally (and this is just me) I would go for the CT100. I had mine in a small living room and was very impressed with it. Now if you had a huge living room or bedroom, I would probably go for the CT500. They both sound great and the CT500 is definitely a considerable upgrade from the CT100. CT100 sounds amazing (especially for the price) in a small bedroom though.