Hi..I've had my Horizon for a year and love it...it's well worth persevering with it. As someone said..it's only a machine, and only concentrate on what you want it to do for now.
One thing I didn't see mentioned regarding the free motion quilting and eyelashing and thread breaking...I assume you are using the adjustable free motion foot that came with the machine? Make sure you have it adjusted so that it just barely skims the surface of the quilt (I found that out the hard way..lol). If it's too high you will get thread breakages and all sorts of problems. There's a screw on the right that raises and lowers the foot. And also, as mentioned, try slowing down a little.
Hope you come to love your machine as I do mine