The 500 has the looks, the first time I saw a 401 I was almost a bit startled. I was more used to vintage and modern Berninas and Husqvarnas at the time, and a Singer 99.
It will be interesting to read first hand feedback from owners. The 500 is very rare here, it was only made in the US factory as far as I now. I assume the 500 and 503 is very similar? The complaints on them is mostly the same as on the 400, they can need quite a bit of cleaning and oiling to get going again. The one thing on the 500 and 503, is the top lid, it's hinged and it can get damaged if it takes a hit. I guess it's nothing you can hold against it, but the 401 always has its' top lid intact.
A lot on these has to do with going over them more than once, taking them back into use, sorting out the minor issues along the way. Some times we need to make an effort to get things working flawlessly. That's why I'm a bit reluctant to say anything too direct when comparing similar models, I know one 401g can sound a lot different than another 401g, but eventually they will turn out very much the same. I can't give you any feedback on the 500, I have only seen one and it came with a Voltage converter at the end of the plug.
Last edited by Mickey2; 01-16-2018 at 11:59 AM.