Personally I think the DTEC is a great system--the only drawback might be the price. If you get the fuel controller/boost controller package you still have to purchase the wideband addition to make full use of the DTEC's datalogging capabilities (you really want to get the DTEC specific wideband so that you can datalog everything through the gameboy interface) and this attachment is quite expensive at almost $400! The boost controller function is nothing short of excellent. You can tweak a lot of advanced settings that I haven't messed around with yet, as well as having peak/hold and scramble boost options and even gear dependent boost levels.
As for the fuel controller bit and wideband addition, I cannot yet tell you hands on how well it works because I have not yet set up the fuel control part of it, but I'm setting that part up this winter in about a few week's time. However, I have looked at the interface of the fuel controller part and it is relatively straightforward with RPM and % tables (how much fuel to add or subtract) as well as some more advanced features that I have not yet delved into.
As for installation: The boost controller is very simple to install. It comes with very clear directions on how to wire it in and how to run the vacuum lines. The difficulty of installing the fuel controller is identical to that of installing a SAFC. They are similar systems, with the DTEC being more advanced and effective. The gameboy is detachable, and is used just used as the interface for the DTEC "thought box" that you can mount somewhere out of the way.