First separate tuners and devices. Some device makers do offer canned tunes with their product, but most folks buy tunes from specific tuners and use the various brand devices to load the tunes (flash the PCM/TCM).
SCT has a few devices (x4 - basic flasher, livewire - touchscreen, itsx - phone app). A SCT device gives you the most flexibility, IMO. You can get a tune from 5star, SVC, MPT, Unleashed, and many more tuners. ...i.e You buy a sct device from say 5star, with tunes. If later u wanted to try MPT's tune, the device will work, just pay MPT for tune files.
Livernois has a proprietary device, so can only use their tunes with it. Not a bad thing, as they had the market share for ecoboost F150s based on reviews. If they wind up haing the best tune, your set. If your not happy with it, and wanted to try say, Unleashed tunes... you would need to buy another device
Cant speak for bullydog device, but believe it is similar to sct's offerings. HP Tuners is also in the game, they have their own device
Feel free to correct me anyone if ive mispoken on these other brands