I love using Bibleworks for sermon prep, but lately I've suspected that it's been killing my Greek skills.
When I come to a form that I don't recognise, I only have to hover above it in Bibleworks to be told the parsing of the word. This means that I don't spend time trying to work it out, and so I don't get to improve my parsing.
So yesterday I decided to prepare this week's sermon the old fashioned way with a Greek New Testament and Zerwicks' Grammatical Analsys of the Greek New Testament. Not only did I feel it sharpen up my Greek, but it was also more fun than staring at a computer screen.