econjack:
Absolutely agree...always use the statement block braces. On the Arduinos, since Serial.print() is the most used debugging tool, you probably will eventually need to "brace-out" the if anyway. As sterretje points out, not always using them is a BYITBL waiting to happen (i.e., Bite You In The Butt Later).
I use them and put the braces on the same level so it's easier to see and follow through indents without matching the open on the end of one line with the close brace. When the open and close are on the same level it's a lot easier to visually find and know the indent level of that code. It's just one possible bug that's less hard to miss.
Note: with the Arduino IDE, use AutoFormat early and often while you code. It will catch mismatched braces and many other errors, make the code neat and show you what it thinks you wrote.