My first impression of the Singer 5500 was its sleek, handsome look, logically arranged controls that are easy to figure out, and things placed where they should be. The stitch selector works well and is intuitive and easy to operate. I checked the quick start guide first, which I thought was well done, then read the operating manual, which was another story. As others have commented, I found the manual a bit confusing and lacking informative detail in some areas. Also too many languages, too much going on and not sure where to look next. A major competing model in price and function (I have one of these too and like it a lot) comes with a separate English manual that's very well done. What makes up for it though is the included DVD instructional which I think is VERY well produced. Although it features the functions of several models, it packs a lot of information that can apply to any machine. It's easy to watch and doubles as a basic sewing tutorial. The competition does not offer this, so score one big one for Singer here.
Turning the machine on, I notice that the LED light is ok but not as bright as it might be. I prefer the competing model I have which has two LEDs and a more pleasing daylight color. But no big deal, it's fine. The auto-threader is a major advance, but read the manual (even better, watch the DVD) and expect to goof a couple times until you understand how it actually works. You'll wonder how you ever did without it. The needle MUST be in 00 position which is the default when you turn on the power, and needle completely up or it won't work as designed.
As far as sewing it's great, quiet, feels sturdy, stitches are tight, no problems at all. The decorative stitches all worked well, and even better when I adjusted the tension (watch your DVD!) and added a bit of home-made stabilizer. It went through several layers of heavy materiel easily, but I was using the right needle, tension, and thread. Don't use old or cheap (hairy) thread, it won't like it but that's true of any machine. The feed dogs have a good bite and work well. They don't drop like they do on my similarly-priced competing brand, but a darning plate is included.
The extension table is sturdy and very useful, and the hard dust cover is a nice touch. The included accessories are basic, but then so was the price I paid so I'm thrilled overall with my deal. I had one minor issue: one of the tabs that snap the accessory bin to the body was broken. Although it stayed in place fairly well anyway, Singer offered to replace it via email immediately so I'm very happy with the way things turned out. I did try to phone and yes, there was quite a wait. I didn't.
So far, I'm lovin' this strong sturdy, good-looking machine with lots of functions and labor savers like the built in thread cutter. I think it's a really fine deal and a great value.