I do know their system worked in the UK for 5 yrs on an ILR visa. Both the family/spousal visa and the ILR can lead to citizenship (well technically Brits are subjects of the Crown). Spousal visa is a bit easier and is what one would expect from someone marrying a Brit. ILR’s are used for students or people working there. ILR’s can be revoked whereas a spousal visa would not be revoked as long as one remains married. BTW it takes 5 yrs before one can actually apply for citizenship.