I have a Brother Innovis 900D. I have issues with it. I have a friend who also has issues with hers. You will definitely be looking at higher end machines than mine, but I would steer you away from the Brother. I feel like I got ripped off, but it was my fault for falling for fancy features and not the guts of the machine. When I took it in to be serviced (again) to a different dealer, they showed me the insides of the Berninas vs the insides of the Brothers. Now I know why my machine was "only" $600.
I would go to the dealer and take a few samples of what you want to sew and some thread. Thread the machine, play with the stitches but do MORE than that. I just ran the stitches down the middle of the fabric and of course, neat stitches appeared. At home, when I tried to sew a purse, I realized that no matter what I do this thing does not sew perfectly straight - it pulls to the side. I had it aligned, cleaned, etc. and it is still nothing like the Bernina I used in class. Sew along the edge, check the quality of the seam... I for one can't sew all the way to the edge on this machine - it stops feeding and the thread gets messed up. I also can't do thick layers (like denim) or it messes up the timing of the machine and I have to take it in to get it serviced ($89). Check the stitch quality (top and bottom) and where all the levers are. I don't use the embroidery on my machine (thought I would) because it's such a pain to switch out to the embroidery foot and it only has a 4x4 hoop. I was a total beginner annoyed by my Kenmore that ate fabric and I did not take my time - I just said "ooohhh pretty!" and took it home. Don't be like me

Erin