Underrated, imo. Shadowdale and the Dalelands don't get a ton of love because it is quintessential Realms and thus attracts a certain amount of grognard hate and young 'un indifference. But you really get a lot within the extended region you describe - plus Anauroch not far off.
I almost said Anauroch and the Stonelands. Sembia too was always meant to be minimally detailed so the DM could expand it. Always wanted to see Sembia expanded on. The Stormweather novels were good.