Well, whether it's worth it is going to depend both on the use case and on the user. (I figure for many folk in this thread, the difference in price is going to be pretty negligible for a tool they use ~weekly.)

For me, I eliminated BC immediately because I was often diffing prose and it didn't have word wrap; that ability is apparently available now in the beta version of BC5, but it wasn't when I was testing it. I suspect it will continue to be non-optimized for prose in how it handles long lines.