Btw, if you never plan to have the desire to use your tuning software to look around, or tweak a setting in the ECM, or do a V-tune type of thing, perhaps the Direct Link thing would be OK. However, you don't get the actual VCI like you do with a TTS or PV or SEPST, all you get is a USB key that is locked to your ECM. The other box that's required is owned by the folks who do the tuning. So you will want to know who else will be able to work with your tune besides the folks who sold it to you. As long as you have that USB key, in theory any Direct Link equipped tuner can use that key plus his box to change your tune or do a new one. You will be required to buy the USB key, plus pay for the tune. I have no idea what they charge for the key, but it's likely to be slightly less than buying the TTS/PV/etc. systems. Otherwise, I can't see how they could claim an advantage with their system.
I'm betting we have some folks on this site who do tuning and who are set up with the Direct Link system. Hopefully they will give you an honest appraisal of the pro's and con's.
Jerry