Problem with any peonies in a small yard is that they'll bloom for very short period of time (7-10 days if no rain) and then you'll be left with a foliage only.
Fernleaf peonies, in particular, have a very attractive foliage, but... in a full sun plant will go dormant in August and you'll have a bare spot till the end of the season, though in z2 season might be not that long at all.
Now, when you know the truth, the call is yours.

I do really like the foliage and right now I'm watching a friend's Fernleaf do its thing. Her's isn't really delicate foliage and has a single flower. I was hoping for a double flower and asparagus fernlike foliage. I was sure that I had seen a picture like that but maybe it was a dream... Diane's peony is flowering now, has been for a week - her regular peonies haven't started yet so I am getting an idea of what all the peonies behave like. Thanks for your advice. Should a peony be planted now or can I wait for later summer and/or fall?

Bareroot peony should be planted in a fall, potted one could be planted at any time.
To my taste double flowering fernleaf look little bid unnatural, not to say fake, but beauty in an eyes of beholder.

Okay - you sold me - I love yours - do you know what its "name" is?

This is unnamed fernleaf hybrid from the Adelmans that retains foliage character of tenuifolia species, but have slightly larger magenta (not red!) flowers.
Link is below.
Talk to Carol. She is really sweet heart and will be more than glad to answer all your questions. Divisisons will be huge and your peony will bloom the very first year.

Here is a link that might be useful: Adelman's peonies.