Registering is good - as long as you make sure remember your login details, security questions and password.
If you forget them, it's a serious pain to get them re-issued and you can't easily use the telephone service in the meantime for buying/redeeming bonds (been there, done that).
I got £25 this month and wife got £75.
But we do have max holdings each , so as expected I suppose.
Most I have every had as a single unit win was £500.
But that was years ago :-(