To the OP: all the partners are virtually the same, and even though their specific response might differ, they don't have any unique comments or dialogue. They all cook (or stop after a few days

), they all open up an invisible shop that gives you 100 gold each day and the possibility to sell and buy things, they all give the Lover's Comfort bonus if you sleep when they are in the same cell (they don't need to sleep).
I prefer to marry followers, to be able to take them along, get the bonus everywhere, and for RP purposes. Two of my characters have gotten married: a female to Vilkas, and a male to Brelyna.