There is no difference except for the exterior graphics. They are "sisters". Wildwood Heritage Glen and Salem Hemisphere Lite have the same line up, just like Flagstaff Classic Super Lite and Rockwood Signature Ultra Lite have the same line up. Construction, floorplans and features are identical.
As a potential customer you can use this to your advantage by shopping both the Heritage and the Hemisphere twins at the same time. Theoretically, you have twice the dealers to choose from, and twice the chance there will be a dealer near you.
There is a tool for locating dealers of those two lines that can be found on the Forest River site
. "Dealer Locator" is located in the upper right corner of the screen. Go to that page and in the "select a product" field enter Salem TTs and FWs, than enter your zip code. Do the same with the Woldwood TTs and FWs.