I didn't know there were dictionaries with four-corner lookup indexes. I've only heard of it in connexion with word processing.

My first ever Chinese dictionary was arranged by initial stroke and stroke count, which was murder on someone who didn't know how to write any Chinese. Eventually, I figured out how to use it, which--somewhat paradoxically--was a great help when I actually taught myself how to write characters.

My teacher has always insisted that learning Simplified is trivial for someone who knows Traditional, but the reverse is not true. However, I'm beginning to suspect that the transition is about equally hard from either direction.