From someone who works on Vintage machines I can tell you two sides to the coin.
People buy featherweights because they are cute and because everyone has oneare two reasons. They're compact which is nice for storage and transport weighing approx 11 lbs without the case.
Down falls- very small bed to turn your work or feed a larger piece through. The tension dial is directly inline with the needle and your line of sight.( because of the small space between gears and levers it is very important to keep up on the maintainace.
The Singer 301 has been billed as the big sister to the feathrweight with a folding extension bed. It is a full size machine weighing only 16 lbs with a built in carrying hadle well balanced to off set the heavier end with the motor.
A number of Japanese makes are great for top stitch work where you need great precision in turning and speed. Not as light weight but nice.
Singer has a long run of well made machines to include the featherweight but then lost that vision and went strictly for profit and bottomed out their quality.
Depending on your need will dictate your purchase. If you are carrying a machine to clases etc look into a smaller machine or lighter weight- doesn't need to be a featherweight or a vintage. For a machine that won't be used much don't blow the bank on it- do some review research to see what people have to say.