I have ONLY seen the Premium tuning on motorhome. Actually, even the utility body work trucks I've seen also have the Premium tune. The Economy tune is optional. Probably for fleets like U-Haul.
Keep in mind the new 7.3L is rated using the Dyno certification method for MDTs. The E-series was not certified using this method previously because of the carry-over powertrains. Ford's fleet documents state that the tuning is the same between the Dyno and Chassis certified motors, with the exception of the Economy tune. The F230/350 are chassis certified, and are rated at 430 HP.
The difference in test methods is boils down to:
Dyno Certification = worst case... All accessories active, and all emissions systems in full duty cycle such as max EGR.
Chassis certification = best case.... No A/C, EGR not active, no torque reduction to achieve emissions limits etc.
So the HP gains of the 7.3L should be greater than they appear on paper. But... there have been some teething issues, mainly with some of the supplied parts like spark-plug wires. It's a promising motor, but I'd personally wait for the Job-2 version, if they haven't already switched over.