No regrets on having purchased the sweet 16. It has worked like a charm and I have no problem working on any of the quilts that I have made (largest is 98 inches so far) and it fits into my sewing room.
It took a while to get used to setting the tension but I love to use decorative threads and I'm always trying something new. It has worked just fine on everything from very fine silk thread to 12 weight cotton and metallic. I bought the couching foot as well and have had fun with that. I always keep a practice sandwich beside my machine and stitch a bit before I move on to the quilt with something new.
I also sit down on the floor to oil my machine. I do not think my machine needs to go in for maintenance once a year(my self oiling sewing machines do) so I clean what I can myself and oil it as per manual. It is very basic so I have never even thought of updating any software.
I got the true stitch and never use it. I can stitch almost as well without it(that took practice)
I got the ruler foot, overlay and the echo feet and use them all.
I have a very bright light overhead because the machine is not that bright.
I tried some others and was happiest sewing on the sweet 16.I felt like I was stitching more consistently and it was not as loud. One of the bigger sit down machines actually gave me a headache it was so loud.
Is there some feature that you are hesitating on?