Comment Explanation (Score 4, Informative) 300
The reason keypads aren't or real ThinkPads is that by including the extra 4 columns of keys, the whole keyboard and TrackPoint (or trackpad, if you're that sort of person) has to be shifted left. This means that you end up either sitting in middle relative to the screen with the hands positioned awkwardly, or having to look at the screen at an angle.
I have a T520 and while I was initially upset that it has huge speaker grilles on both sides, I actually came to appreciate this decision, though admittedly it would suck if I had to punch in numbers into a spreadsheet all day. Just get a ThinkPad and this baby