SumikoKeel,
As the owner and user of several Kenmore 158- series of machines I will say this. They are excellent machines and will do what you need done. They are not user intuitive however and you do need the manual to get the best out of the machine. If you follow the instructions to the letter you'll get a great stitch no matter which one you're trying to do. If you don't follow the instructions ...... well I shudder at the thought.
If you are looking for a Singer machine to do straight stitch quilting or multi layer stitching I'd suggest the 66-16 or the 201-2.
They both have bigger arches than a 15 giving you more work room.
The 15s are said to be better at FMQ, but I can't say this from experience. As I don't FMQ at this time.
None of these is fragile at all.
The only thing about the potted motor machines ( 15-91 or 201-2 is they are not as easy to work on as an external motor machine. They have their benefits too, no belts, direct gear drive and no slippage is one of them. The motor not protruding into the arch space is another.
The Kenmore in your original post is over priced without the manual. Considering the driving distance I'd pass on it.
Are you looking for a cabinet machine or a portable?
Joe
Last edited by J Miller; 12-02-2013 at 08:14 AM.