They're seriously almost identical. I used Secure before Bambino was released and transitioned to Bambino immediately when they were released. I have never had a problem (hundreds upon hundreds of diapers later), similarly to not having problems with Secure.
Simply put, they are both excellent products. Probably the best on the market, in my opinion, that I've tried thus far (and I have used Abena/Molicare/many many many others. They aren't even 1/10 as good as Bambino or Secure, in my opinion, for several reasons).