Also, ergonomic wasn't the right word to use, more like, the layout makes more sense. Keys are in a better position.
right, the older model you refer to has same or similar keys as X220/X230 thinkpad then Lenovo switch to lower keys anyway this is probably very individual choice and also when you already have one KB and you are used to it and it is fully functional, there is no reason to look or try any other model ;)