The perfect machine is whichever one that's right in front of me.
I have about a dozen machines now too, and there isn't a single one in the "family" that I don't like. Whichever one I've sewn on the most recently always feels like my favorite, then I use a different machine and I fall in love all over again. Each one is special (to me) in some way or another and I tend to pick my machine based on my mood. Some days I want everything as automated as possible; other days I want to play with cams and levers.
I haven't tried FMQ on any of them except my Janome 6600 though - that big harp is there to be used! And that machine does everything else I ask of it very well too, no complaints other than it's too big & heavy for me to consider it portable.
My current "perfect" piecing machine is my Singer Rocketeer that I just got for Christmas. Not only is it completely awesome to look at, it sews a
really nice stitch and had a perfect 1/4" seam without any adjustments - only machine in the family that has that. That machine is just beautiful, inside and out.