+Haltech can be tuned in Real Time, meaning you don't have to turn off the car and load a map.
-/+ Everything is done by bar graphs (3d), meaning you don't manipulate numbers, just tweak graphs (dunno if that is a plus or a minus).
+Built in boost and idle control. Don't need to spend extra money to achieve these features.
-Uses stock sensors so a higher resolution crank sensor is not an option. Tuning to the ragged edge could get you into trouble.
-No high-output ignition coils. Can be purchased seperately, but this is the same as the Tec.
Haltech - $1200
not sure about injectors
difficult to install yourself
no real basemaps available
Tech II - $2500
completely bolt on
comes with base maps
Just thought I would add a little to this discussion, since I am now researching engine management.