First, if you have t buy one of the two and there is no difference for you, get the 60D. It is a more advanced camera and much easier to control because of that, although image quality is very similar.
The perception of better focus from the viewfinder probably comes from the the fact it is more than 10% larger. The bigger the viewfinder, the more details you can see and that contributes to your perception.
The 60D has a more sophisticated autofocus system so I expect it to be faster. The 60D has more sensitive (cross-type) focus-points so it can detect autofocus faster. If you switch to center-only focus-point, the difference will diminish, as you will be measuring cross-type vs cross-type AF speed. That does not mean it will be the same, just closer.
Finally, you did not say if the same lens was used on both cameras. That can make a huge difference. If it was not, then no comparison of focus speed would have much validity.