Also just a pet peeve difference in construction between java and the new version. When you hold a construction element, say a beam, with the grid turned off by default it sits flush with the surface you are pointing at - this is like the java version and I like it. However if you turn grid on, the beam goes through the surface you aim at, leaving approximately half the beam above and half below your cursor. This makes it really annoying to place vertical beams of the desired height when the grid is on. In the image attached, the two vertical beams are the same length. The one on the left is placed with grid on, right with grid off.
In Java it's the same. To avoid this either use a smaller grid, as Groovaholic suggested, just make a shorter beam or simply use pgup until its above ground