as said the zed is very smooth and linear with its delivery, the GT4/Leon are like old school turbos nothing nothing, wham, change gear. Also the FWD in the leon adds to the feel of speed as it simply doesnt put it down like a real car should Gearing everything comes into it. The Zed is a GT car over anything else and a fantastic one at that, very fast just without any of the drama.
As a package car I have failed yet to find one that matches the Zed as a total package. The m3 is nowhere near as close for overall ownership and the zed outhandles/brakes it. Ultimately the zed is let down by the lack of rear space (though we managed 2 week tour of France comfortabely) and the older ones did suffer from a lack of top end rush (compared to the m car).
What you do get when you get a Zed is probably the best car in its class/price bracket. That of course will sound biased due to being an ex owner but I became an owner for a good reason and regretted becoming an ex-owner the day I sold it!
If you want the urgency of power take a look at other cars in the same price bracket such as the Monaro (hehe not going to try and flog mine in this thread) as they are phenominal cars for the price, however, from factory you do need to do some modifications to get it where it should be. The zed came from the factory as well set up as anyone could have wanted.