Physically, you can install on a 6th Mac.
There is no awkward activation key procedure when migrating licenses.
perfect, thanks.
Regarding your soapbox speech: that's ok. I'm not going to abuse the licence, I will pay my share.
I agree with you on your commitment to customers' honor. The low fees for SL do really make it easier on this, too. (as apple does in general. although I sometimes doubt if they fully earn this support by their customers/fans. sometimes...)