06 4.3L Silverado computer mods

I see that Hypertech and Jetchips now have tuning software/hardware for this model. It's nearly $400 for the laptop version so I am hesitant to spend money before reading reports. Has anyone tried either of these and do they work? Any problems?

From what I've heard, handheld tuners are a waste of money. Cutom tunes such as Nelson, Wheatley, Wait4me, ect are that way to go. Can't speak from experience though.

The tuner in question is laptop based and could work if the software and documentation are any good. That's a big "if" and that is why I am waiting for reviews.