Like a car -- the test drive will help you decide! You can eliminate the ones that "just don't feel right". One of the problems with many of us is we love our machines -- so much so that we keep them a long time! So making a change means all the changes in machines over these years are now available to us all at once.
Have friends who have newer machines? What do they like and not like about theirs? Can you come over and see? Try theirs? Make notes on what you liked about the features -- most brands have many of the same features, tho' they might work a little differently. There will be some you couldn't care less about, others you "have to have". Before you start going to the shops, where the pressure to "take it home" and the desire to do just that, might eliminate giving more machines a test sew.
The more decisions you make before you go to shop, the happier you will be with a machine which will bring you joy for years to come.