There are different levels of machines for both stand alone and combo. If a person compared a low end stand alone to a high end combo there probably is a difference.
My dealer sells a lot of embroidery only machines, most are commercial level and they have some really neat options you can't get on a combo machine because of the shape of the machine. The quality is as good or better than the high end combo machines. No idea what hoop size you can go with them.
My new machine is the Solaris and the largest hoop (with the upgrade) is something like 12*16. My embroidery is almost all for enhancing quilts, so I love the big frame. I have a 12' LA, so don't plan on doing any quilting with the Babylock - other than playing with some trapontu possibilities. I do like the quilting motifs to embroider on blocks, but I'll add batting and do the quilting after the full top is assembled.
BTW - my dealer has a really good deal on a lightly used Babylock Destiny right now!