My system uses the Baby Lock with 9" throat. I can do a 5 inch pattern on baby quilts through full size quilts, but it is very difficult to even do a 5" pattern on a queen size. So with a 11.5" throat you could probably do a 6" pattern. My suggestion is...if you can afford a larger throat machine I would not get this one.
The reason I purchased the system I have is because it is the only one I could afford but it is time consuming to do such small patterns. But on the bright side, I can quilt my own quilts and every now and then I even quilt for friends and make a little extra cash.