I have a 16 and love it. There is a monthly class from handiquilter and it has given me so much help. They explain the tension problems and the use of rulers. I would buy another in a minute in case mine died.

I’ve had mine for a little over a year now. Absolutely love the machine. Don’t really have trouble with the tension but it does have to be adjusted for different types of thread. I have used 100weight thread with it with no problem. I did slow the machine down for that but otherwise it ran like a dream. I also do a lot with Superior metallic thread and that also runs like a dream. So far I haven’t found any thread it was really picky about.
I didn’t get the stitch regulator, nor did I get the extensions but I bought an IKEA drop leaf table that folds up to about a foot wide and has drawers down the center. The top is just a tad higher than I have the machine table set up and I keep tools and threads in the drawers. Can open it up when I need it. Works very well.

I've had mine for about 6 years. I Absolutely love it. And the service at Friend's Quilting Basket in Lake Odessa, Michigan cannot be beat!!!!! (No, I'm not affiliated. I'm just a grateful customer.) It is worth the drive there just for the service. And I don't feel bad about driving right by the door of the other HQ dealer. Nope don't feel bad at all. Just loving my Sweet 16.