I love my bernina, not because it cost more than other but because it helps me quilt with precision. When i started quilting i had a kenmore and old viking i got at yard sale. Yes it made perfect straight piecing. But when i really started free motion quilting and spent hours of frustration due to tension problem that is when i asked dh for a good machine. I can do a king with my bernina but still limited. Yes the long arm would have made it look better but i am content with what i have.
i believe some machines will limit you on what you want to do. Just don't try putting your focus ford car in a racetrack and expect the same performance of what u would from a corvette.