I can only offer comparison to a 9700... but on the 9650, the keyboard a curvature to it... and although the keys are the same size as the 9700 (I have both - for now, selling the 9700 soon)... the curvature has the effect of opening up the keys from the standpoint of one's pecking thumbs... so it makes it feel larger than it is...
feel wise, i'd say it *feels* somewhere between a 9000 and 9700... closer to 9700 of course... but it's how I would describe it overall...