So I recently bought a 08 6.4 and want to do a doc/dpf delete and tuner. I am going back and forth between the spartan and h&s. I think I am going towards the h&s. But after reading on here and other forums it seems like their are loads of issues once these tuners are installed? And what is the transmission learning all about? How long does it take? I previously had a 06 6.0 with an edge programmer and it seemed like a piece of cake to these tuners? Also the different trans. tunes seem confusing. When does the TC lock now on the factory program? Thanks for the info guys. Any input would be greatly appreciated.