I will give this a try. For many years I had only one machine, but things have changed.
-- I have a lightweight machine (Janmome 3160) that I take to class. I will use it for piecing if I want to sew upstairs instead of the sewing room. It has a great assortment of stitches and many of the features of my big machine.
-- I have a machine that I use for most sewing and piecing. I sometimes call it the beast because it is pretty heavy and I hate taking it anywhere. It has a great straight stitch and some really cool decorative stitches. I can quilt some decent sized quilts on this machine because it has a very large harp, but when I don't want to have to handle a large quilt, I have another setup.
-- I have an embroidery machine. Since it can take a while to stitch out a pattern, and since I have to be present to change threads, I rarely use this for anything other than embroidery, I use my regular sewing maching while the pattern is being stitched.
-- I have a Grace quilt frame with a Juki on it. The Juki is only a straight stitch (but a wonderful straight stitch). However, it is a hassle to take it off of the frame so I only use it on the frame.
I have not spent a ton of money on my machines, but they do a great job for me.