Here's a case you should be following which involves both public use and just comp issues, now before the Louisiana Supreme Court.
The case is an appeal in an expropriation case from a quick-take of a Mississippi River docking facility downriver from New Orleans. The Port took the entire VDP facility, made no change in how the property was used, and eventually turned over operation of the facility to a "hand-picked" private operator.
In St. Bernard Port, Harbor & Terminal District v. Violet Dock Port, Inc., LLC, No. 2016-CA-0096 (La. Ct. App. Dec. 14, 2016), the Louisiana Court of Appeals, over a strong dissent, rejected the owner's arguments that the Port could not take the property for economic development, the taking was for private benefit, and the argument that the Port was really taking the property in order to obtain VDP's contracts with the Navy. The court also upheld the "fair market value" standard for calculating compensation. The owner filed a writ petition with the Louisiana Supreme Court.
There's a lot going on in this case, and it has attracted national attention with multiple amici urging the Supreme Court to accept the writ and review the lower court's ruling:
The first three briefs focus on the power to take and public use, while the Owners' Counsel brief examines the standards for just compensation. On that latter point, the owner is arguing that because its property is unique, the lower courts' sole reliance on fair market value as the only applicable valuation standard was wrong, and that evidence of replacement cost should have been admitted. [Disclosure: we helped draft the OCA brief.]