Excellent. I'm using this to test a custom SSL application. I was able to convert my test script from IO::Socket::INET to IO::Socket::SSL very easily. The only problem I had came from using send/recv and reading the documentation quickly cleared that up.
IO::Socket::SSL is a great module. I use it a long time and I'm very satisfied with it, because it's really easy to use. So I think that a rate of 5 is alright.