You must realize that a design ANY machine stitches out is only as good as the digitizer created it - the machine only puts the needle down wherever it's told to. If you have a demo, the dealer will probably use a design built-in to the machine, so all machines should produce the same finish using the same design.
Be very choosy re buying designs - one can be overwhelmed by the masses on the internet, and you can end up with thousands of them, and hardly use any - also many are not well digitized.
Yes you do need a small software program to read the designs - shows them as pictures, not a list of names or no's. I think all brands should include one free with each machine, and dealers should explain how it works , before you purchase.
Also a brief explanation of what one needs, stabilizers, tear-away, cut-away, water soluble, types of threads and their differences. My Brother machines take all kinds of threads, so I don't believe in the 'best quality' spiel. There are some rubbish ones out there, but if it's smooth, fine and shiny, doesn't fall apart, it should be good.
Another decision is the size of blocks you plan to embroider. Do you just want to make labels or put names on things, needing a small hoop therefore a low end machine will do - or would you like to make, say quilt blocks, large, and need a large hoop provided by high end machines. How much embroidery will you want to do.
I am not a great fan of todays big machines, as all the new bells and whistles seem to take up more time, whereas the older ones, you mark your centre, put the hooped fabric in and away you go. Also some machines are simple to operate, whereas others are darn difficult.
Hope I've helped.