It makes life easier to have the same stuff. For one thing, any spare parts you carry with you will work on both sets of gear. (My husband and I had different regulators for a while, and the DIN o-rings that fit one didn't fit the other, and we always seemed to have the wrong ones with us.) For another, each of you will be intimately familiar with the other's equipment, which makes spotting something that's put together wrong or disconnected much easier.
I dive in a small corner of the diving universe, where everybody has pretty much the same gear. I can't tell you how many times that has come in handy, when something breaks or fails and you have to borrow something . . . and it feels and works just like yours.
I dive in a small corner of the diving universe, where everybody has pretty much the same gear. I can't tell you how many times that has come in handy, when something breaks or fails and you have to borrow something . . . and it feels and works just like yours.