I'm busy trying to get out of debt, so I wouldn't buy it on a payment plan. If you put $108.23 away each month, how long would it take to save the money since you wouldn't have to pay interest?
I would start a fund and start putting the money away for a quilting system and then start looking for a good buy. The good buys do come along.
I know that your question was whether the HQ Sweet Sixteen was worth the money. I am thinking about buying the HQ for my quilting frame (I like the frame more than sitting at the table). There is an HQ 16 table model forum in yahoo groups. The group is for people who own the machine or who are thinking about buying it. You could request membership in the group and just read the people's comments about any problems that they are having with the machine.