I am the spreadsheet queen. Whenever I am making a purchase that involves many different makes/models of an item, I make up a spreadsheet and do like Tartan says.
I list the features I want/need; prices; warranties; etc. and use that as my guide. When I purchased my Viking a number of years ago, I got some extra features (some embroidery stitches) that I wasn't interested in but it did have all the other features I wanted. And it was a price I was willing to pay.