If you can afford a specific machine and you feel it makes your hobby more enjoyable why not?
For me, I like the extra harp space. It makes things a bit easier. But If I were making a very large quilt
I would send it out to be quilted or borrow (pay for time) on my nearby dealers long arm, quilt set up.
If you like the large decorative quilting stitches, the 9mm machines have thier advantages. If you like easy as pie piecing I favor 5.5 mm machines, or a straight stitch machine like a feather wieght.
If you like to free motion quilt I favor a Bernina with the BSR.
Maybe you need to keep quilting and then figure out what you need for the type of quilts you are making.