Comparing the Mclaren to the GT is very difficult. I have only driven the Mclaren 2 times so far but I did have a chance to push it a little last night. It is a much more refined car and obviously has all of the electronic help that is almost totally non existent on the GT.
I have always preferred the no thrills race car ride crowd having owned a replica M6BGT several years ago with a real aluminum tub and the suspension from a Lola T-70 etc. I now have a Mosler and a 1985 Countach in the other garage, so even the GT is a big step up in comfort for us. The Mclaren is a world apart from what we are used to at least for comfort and drivability.
My first impressions of the GT was that it was difficult to see where the fenders were and there is a huge blind spot from the pillar and mirror on the driver side.
The first impression both my wife and I had of the Mclaren was how incredibly easy it was to drive and how easy it was to see everything. My 16 year old son is out with my wife right now driving the car. My wife drives the Countach and the Ford GT but she does not like to drive the GT unless she has to. She is very uncomfortable with the feel for the corners of the car. My son feels the same way about all three of the cars. (they just got back). Once again he thought it was easy to drive but complained that he lost the paddles when turning the wheel.
My impressions so far are that it is faster then the GT (650HP) and will handle better as well. I am always worried that the GT will swap ends on me like it has for over 1,000 other guys, so I am a little extra careful with it. The GT feels wider when driving it and you feel like you are in the middle of the car length wise. So far I feel like I am way up front in the Mclaren like a twin engined or jet airplane. I definitely have the feeling there is a lot more car behind me then I perceive it to be.
It is not as fast as the Mosler and doesn't seem to handle as well but the Mosler has over 800 HP and only weighs 2,400 pounds, no power steering or brakes and no rubber suspension pieces at all.
So far the Mclaren is a definite keeper. A car that we would likely drive when we would not take any of the other cars.