As the chips in our cameras continue to grow in size the "problem" you're having with focusing is only going to get worse. As as the chip size increases, this interacts with the lens reducing the depth of field. Most people see this as a benefit because it makes the footage more cinematic as everything isn't in focus. A nice blurred background makes your subject really stand out. Some people refer to this type of image as having depth or being 3-dimensional. This is also the reason people purchase depth of field adaptors (Letus, Cinevate, Red Rock, etc....) Correct focus is CRITICAL when shooting with an adaptor just like it is when shooting a major motion picture. (why Hollywood hires "focus pullers" to maintain sharp focus)

But you're correct, if you're used to shooting with a very wide depth of field (normally because of the small CCD chip(s)) then it's going to take some getting used to.

Just thought a little background was in order. :)