I have the Brother Quattro 2. Love this machine. I have owned brother machines for many years (also New Home-Janome and Elna) and have never had any problems with any of them. Finding a good dealer is important. I use almost everything the machine has except the knee lift...just not used to it yet. I need to take more classes to use some of the features that I did not understand at my classes.
My warranty is fantastic. I have not used it for this machine , but my last brother had a major computer issue. So bad, it had to go back to the factory. They repaired it very quickly, updated the computer, fixed a timing issue and replaced a foot that I had a bad nic in. ( the computer issue caused quite a bit of damage to parts) I paid for shipping, but everything else was covered by warranty.
Buy the best you can afford.