Thats a really interesting question. We have been together 20 years and I love him dearly, as he loves me. We have had a rough time that lasted about 5 years, we are over it, but its not the same - but thats life isn't it, having children and debts and job worries get in the way of romance. So, id not leave my partner and i'd die for him. I believe he is my soul mate.
We have changed though, drastically from how we were - older and wider wiser. I miss the romance and that feeling of butterflies etc. So when i look at him do i see someone who i would choose as a partner?
Yes, yes i would, id do it all again - well not all of it, id do quite a few things differently but my DP is wonderful, kind and sexy and amazing in bed (of course i woudlnt know the last bit) and sometimes (i think this is due to my bad eyesight) if we are separated in the shops etc and i catch sight of him out of the corner of my eye, before the message gets to my brain, "oh, its you" i think "phwoooarrr hes a bit of alright" 
I wouldn't want to ask the same Q though as im not so sure i'd like the answer :( I don't recognise myself compared to the person i used to be and i often wonder how people recognise me in the street (im not sure thts normal ti feel like that, but thts another thread)