I think these are two slightly separate issues, Marg:
"If you are taking a dish to a friend's dinner party and the host is not really a stellar cook, do you make a simpler, less unique and less enjoyable/exciting dish (basically to match the rest of the meal),(...)"
Yes.
"...or do you go for an allout culinary experience for the enjoyment of the other guests, and possibly at the expense of your hosts?"
No. (Technically, you/one can do whatever one wants, but I think the gracious high road is to let the host/hostess shine at his/her party--whether that shining occurs in the kitchen or not.)
"I thought that I was going very plain and simple with this soup, for just that reason, but then there's the fellow who responded in a bit of an embarrassing way. So what do you shoot for: the better enjoyment of the guests or the comfort of the host?"
The guest of your friend is at fault, in my view. No doubt the soup was worthy of the praise and the compliment, but to throw over the entree for it is immature. Maybe I'm erring on the formal side--this is probably not a big deal if the host/hostess's skin is thick, or if it's a chili-and-beer potluck--but the friend's guest's behavior strikes me as rude.
I think you wisely made exactly what was called for, and the problem arose only when the guest went a little nuts. smileys/wink.gif
Just my two cents. smileys/smile.gif What did you think of the guest's behavior?