Don't get me wrong, I love the Z51, but the AWD cars are really awesome. But like you, I went through a very expensive learning curve with those cars. The WRX was the beginning. After discovering that the power was not easy or inexpensive to increase, I bought the first EVO VIII that came to Atlanta. I let myself get talked into an "up-grade path" by some tuner wannabees and ended up totally screwing up the car and spending almost $10K doing it
I can laugh at it now, but I sure was frustrated then.. I remember though, all the other motorheads in the forums went on and on about how much better their EVO would be as a daily driver after installing the twin disk carbon clutch, the racing springs and coil-overs, replacing the ECU with the stand alone EMS, cams, bigger turbo, bigger injectors, etc., etc.
It was ridiculous, I was having first hand, nightmarish experience with all that crap and they still would say how great it was working for them. Of course, it was total bull****. Any time you modify a car to that extent, you've made some pretty big compromises trading driveability, comfort, reliability and lots of $$ for more power and all the crap that goes along with it to handle it.
Since I'm pretty incurable, I will probably mod my Z51, but I hope I will use more caution and use a systematic approach. I think that now I understand how it works and what exactly I'm trying to accomplish and why....