i still really believe in kenmore. one huge difference i see between the one you've chosen (on sale for $199) and the $254.99 one is 9 month full vs. 25 year limited warranty. granted, the $254.99 machine is computerized.
i did notice that neither of them include the even feed (walking) foot for quilting. but you can purchase that separately ($19.99). your wife will want that for even the basic straight-line quilting.
looks like the throat on the $254.99 one may be a little larger (could make a difference when she really gets going with quilting when trying to maneuver a piece through).
just to stir the pot! have fun!