Sorry to hear of the news Ian, hope you get a good pay out if it is written off.
I dont own an Evo, but one of my best mates has one and I've been out in it a lot, on the road and on the track. They are an awesome beast, but a weird one. As breay has already mentioned, in a straight line there is not a lot in it, in fact it is so close its very much down to the driver. Sometimes I get away from the Evo, sometimes he does me, just depends if either of us have any slip ups on the way with gears or traction. Also they are awesome around the bends, but so is the Zed if driven right. In the rain, granted the Evo will win, but I feel a little like a passenger in the Evo as apposed to the Zed. Why? Well because of all its electronics, you can stick it in a corner, boot it and it will track you though. With the Zed, you have to feel your way in and out of the corner, not giving it too much stick, but the reward for hooking it all up is massive. Round a dry track there is nothing between the Zed and Evo (FQ300), but the Zed is more rewarding as you are in control, not the YAW sensors and other electrics. Also the ride quality is vastly different. The Zed is firm but forgiving being that its a GT car. Its compliant, but on a track is somewhat lacking. The Evo swings the other way. On the track its brilliant, but I wouldnt like to do a long journey in it on the roads, not compared to the Zed where I have done over 350miles in one go before!
So afraid to say, you need to get out and try one (or two or three ). Although on paper the Zed and Evo are pretty similar, they are miles apart on everything else, from ride quality, comfort, noise, handling (more the way it handles rather than one being better than the other).