It may be more having a vertical bobbin vs horizontal, Singer 15's are know to be great FMQ machines.
My last quilting machine (Bailey) was oscillating - my new one (Handi Quilter) is full rotary.
For a domestic machine, it's all going to depend on the machine. My best "all around" sewing machine (viking bought around 1981) is not very good with FMQ. So try your machine and see if you like it - and if not, then try something else and keep it for piecing.