Different symbol entry modes -pros and cons.

This may simply be my personal bias, but my feeling is that although plopping symbols on the staff with the mouse may seem like the more intuitive way to enter symbols, this soon becomes tedious.  If you do like to use this method, however, you should check out Symbol Entry Tips to see how to do mouse symbol entry most efficiently.

Entering with the keyboard may seem intimidating when you think you have to learn many keyboard codes, but in fact the most useful codes will very quickly be learned (especially if you know the rationale behind the codes) and then it becomes much quicker to simply type "q", "t", "h", etc. rather than dragging the mouse around and trying to click it on a specific staff line.  Also, once your hands are on the keyboard typing music in you will be more inclined to use keyboard shortcuts (such as Ctrl+A to insert a tab line) and  insertion shortcuts which speed things up even further.