I have one Flat Wonderful peach. It’s not recommended as a commercial variety, but truly makes a very nice backyard tree, in my location.
I’ve had this tree for about 7 years or so. It’s a consistent producer of some fruit every year. Produces beautiful lavender blossoms, and red foliage every year.
The flat fruit are enjoyable (though not the very best flat peaches). I’ve also watched an unmanaged specimen close by and it does decently for an unmanaged peach tree. This tree is a definite winner in the backyard category in the area, imo.
Here is a pic from this morning. I’ve raised over 100 different peach cultivars, and this is the only one I’ve raised which has red foliage like this early in the summer (as the summer progresses the foliage turns green like other peaches).
I agree the Flat Wonderful is a very attractive peach, I grew it for several years and got comments on it. Another peach I get comments on are the double blossom ones - it is a genetic variation in the flowers where they have double the petals. Red Baron is one.
I recently discovered another unusual peach, its a weeping peach which also has double blossoms. It is fruiting for the first time this year so we will see how good a backyard variety it is. The variety is Hong Chi Zhi, its something I got from the USDA. I wished I had grafted it higher, its low and is not gaining much altitude.