Both will do the job... . EFI is a vast and enumerable program... . a good programmer can write some code that will work very well, and for a long time. There are quite a few dealers out there who can work with it. It sounds to me like you will get a FlashScan tuner with the programs loaded on it, which will VIN lock when you program your truck... . SOP for EFI dealers, who have to purchase liscensing to program individual VINs for different trucks. Basically, it works the same way as a Smarty, only a little more advanced, and can be reprogrammed at later dates. The Smarty's use a generic program, that works well for all trucks. EFI is tunable to your individual truck. I believe there are 36 parameters that be read and used to tune for power, mileage, or overall torque.
Even EFI is feeling the pressure from big Brother. They recently upgraded to 8. 0 from 7. 5 versions... . the new version has the DPF parameters, but they are hidden. IT takes a smart and capable user to find and initiate them... . They are out there, just harder to find.
Either version has it's ups and down, just like anything. Personally, I like the EFI, as I can tune the truck, with it's own specific tune. But I have the software and boxes... . And any of the tuners will up your power, just from removing the DPF and advancing the timing to increase mileage.
Smarty programming to remove emissions is dubbed ". ME" and is no longer being programmed here in the states... . There are some boxes being hacked and upgraded to the delete programs... . Beware where you buy, as hacked boxes will have no warranty, if my understanding is correct. Smarty products sold from Ebay are not warrantied, either. Smarty does a good job with their software, IMO. I've seen some trucks with several hundred thousand on the clock. They all gain substantial mileage when this is done. One I saw recently went from 11-13 to 16-19mpg, usually pulling a heavy bumper pull trailer... .