I hope you don't mind, but I will repost what I wrote in the original thread, and change it up a little:
I am a person that learns by doing. After doing all the reading I had a nice ideal about what I wanted, and thought that I knew all about what I needed out of poly (that would have been 15 years ago). Experience has taught me a lot, including that I had much more to learn about what was important to me in life, and I haven't stopped learning and I continue to refine what my "ideal" is, or even if there is one ideal for me.
My "perfect" poly is having a long-term committed romantic loving relationship with one or more people who can respect each other for who they are with no attempts to manipulate or change the others - I think that from a purely practical standpoint my limit is two (based on current and previous experiences) - my idea of being in a committed relationship means devoting time to each, and I think more than two and I wouldn't find I could devote the necessary time to each. Living arrangements are negotiable as is whether the two of them have anything beyond a functioning friendship. If they choose to bring others into the relationship then that is totally cool by me too, and I don't mind what sex their partners are.
I don't know that I focus quite so much on "perfect", though - I have some needs which a relationship configuration needs to fill, and some wants over and above that. As long as the needs are met (and everyone else's who is involved) then I think I am quite flexible.
I feel blessed to have a wonderful relationship like this for over a year and a half now. I have had others that have been learning opportunities and good in themselves but this one is by far the best.
"Listen, or your tongue will make you deaf." - Native American Proverb