I am not sure with the 1.67. However I have a 1.5 and when I am using it on my lap it does not get too bad ( however, everybody will have there own opinion) but I use it with the performance set low for battery life. this is because typically I will only set it on my lap in the recliner while surfing the net (no need for the extra speed). On the second hand, when I have it setting on my desk while playing Warcraft or something it does get rather warm around the hinge area and on its underside but i have never noticed the area around the track pad getting warm. Hope this helps.