There are differences in the characteristics that are common to poly relationship types. One of the broadest gulfs is between domestic and non-domestic partnerships, or what some of you might think of as primary and secondary relationships.
When you are living with someone, there are more things to consider than whether you want Thai or sushi on your date, or how to find a convenient spot to snuggle up in for an hour or two of bliss. There are all the practical details of life that need to be covered and accommodated, chores, work, kids, being sick and paying bills.
Largely being a domestic partner currently, I find myself yearning for the free-spirited nature of the non-domestic partnership. It isn't that I want to divest myself of the responsibilities inherent in living with PG and S so much as wanting to "be the girlfriend" a bit more than the domestic engineer part of the time. I envy the urgency and wanting that is often part of non-domestic equation, when you don't see your lover often and are SOOOO ready to rip their clothes off and romp all that frustration off, and it's an event to spend time together.
How to work around that dynamic, or being able to manifest a portion of the sheer fun within the context of being the domestic partner can be quite a challenge! We do "dates", try to go out to events, show appreciation in small ways and significant gestures, but under it all things are just a little different.
The love that I have for the people I live with is complex and nuanced in ways that I haven't experienced with non-domestic partners. Continuing to stay conscious of that can be tough when it feels like someone else is getting something I want from my partner. However, there are pieces that I receive in return that are also unique to our connection. You can't have it all, all of the time. What I have I am grateful for though, all of the time.