My thinking would be to go full speed ahead! Bernina introduced the 8 series already. They introduced the 3 series machines. The 3 series is below the abilities of the 640. The 8 series would be my preference. The upgrades you fear are already out in the 8 series, and if they don't interest you the 640 is an excellent choice. It also gives you a great deal of flexibility with embroidery. I like the start / stop button which is not available on the 730. I think you will be very satisfied with the 640.