Actually I think you might need to go back and research SCT. They are by no means Generic Programs. They are custom tunes also. You actually call a third party tell them your VIN and what you want and the will design a program for your SCT programmer. SCT and even the Edge Programmers are specifically designed for the 6.4 . Why you would need anymore than 3 programs (Econo, Tow, Perfromacne), well I guess that is your choice. As far as the 580 hp give me a break. You must have more money than well, whatever. You are already taking the chance of really messing your 6.4 up anyway no need to do it any quicker. Unless you are strictly racing your truck no public road driving then I guess go for the spartan. But it just not worth the money. You can do everything you need to do with the SCT (or the Edge for that matter) but again its your money.
You really need to do some research, not just on programmers but on diesel engines too. You are not going to do everything you want with just a programmer. You really should do some mechanical mods to properly acheive the hp gains that Spartan is claiming. I have been mesing with cars and trucks a long time and If all i needed to do was buy a programmer to get all that well, there are alot of people that are doing something wrong!!!!!!