Which one of us, me or artlady? You mentioned us both :P
In the event you meant me, about the only thing I can add is the biggest problem I can think of.
And that's the older partner treating their younger partner like a child. Its hard to avoid. But not impossible.
No matter what your age, a relationship must be EQUAL. I learned this the hard way, but not in the age sense. My husband is older than me, but he has a mental disability so in many ways I am older than him, and I used to TREAT him that way... a BIG no no!