I have this strange notion that modern sewing machines will never appeal to me because of weight issues: they are just too light to be reliable. I'm really not sure where that came from, except that I remember using a friend's machine in highschool and it bounced around and made things difficult. Probably that was more due to the table it was sitting on - some sort of boards piled on plastic crates if I remember correctly - and less on the actual machine, but it seems to have stuck.
This machine of mine certainly meets all requirements for heftiness. It is old. Quite old. But it has character in a way I am just not convinced a new computerized machine can have. Sure, it drives me nuts with the threads getting caught up in the bobbin, and there are no settings for automatically stitching perfect flowers, but it does have a wonderful tin full of attachments that I do not know what to do with (I don't have a photo of that now, but will add one soon in case anyone cares to aid in identification...).