You are going to love it! I just got the Unity. Had actually planned on the Crescendo but decided that since this is my LAST machine, I would get the combo for what little embroidery I do. I have a 5x7 but that 7x12 with a color screen was a deal breaker! I haven't been able to take any lessons yet and boy, is it intimidating on my own! Ive got a wonderful dealer tho, with life time lessons, so just have to find some free time.
I also have the Symphony and the Serenade and don't see too much difference with the way the Symphony works, except for the extra bells and whistles.