First, if you have not opened the packages and Advance Auto Parts has a store near you: Return the blades to WM and order them online from AAP, with one of their 40% off discount codes. (TRT41 is $40 off a $100 order, and DOW 44 is $50 off $125, last I looked. If that has expired, there are always new codes. See the Product Rebates forum.)
That should save you enough money to make it worth the trip to the stores.
As for the Latitudes: Excellent blade, especially for winter. I have them on my Saturn, installed last November. The debate now is whether to replace them for this winter. Conventional wisdom from online reviews is correct, in my experience:
They are no better (or worse) than standard blades in ordinary rain or non-frozen precip. They really shine in winter, though; ice and snow do not build up on the base of the blade (not sure what is the technical term for "base") due to the way it is constructed. Plan on at least a solid year out of the Latitudes. Anything beyond that depends on usage, climate, vehicle, etc.
Some reviewers claim the Latitude does not adhere to the shape of their windshield very well, but I have found just the opposite. That's vehicle-specific, I suspect.
If you drive in winter weather and got a good deal on them---with a probably better deal available at AAP---it's definitely worth it.