If your gonna get a base model use it for just that DD dont even bother messing with it, you wont ever be happy with it, but if you get a gst/gsx they can get very expensive most are not very reliable unless you replace everything.
if you watch the tutorials on the ecm link website you can get yourself a basic tune done yourself, im a beginer at it too otherwise i would help you out.
Everyone alot of everything, you usually dont see to many dsm though usually everyone is working on them lol I havent gone out there in a long time though so im not sure how its been recently.