I was wondering what you meant by last line, because your question had nothing to do with key server options. So, I interpreted it as "the last line of the block about cipher preferences". To answer your question, yes that changes the default from CAST5 to AES256. The ciphers are ordered by strength (ie, safety), and as you can see, CAST5 is pretty far down the list. The advantage of using CAST5 is en/decryption speed and compatibility with many encryption programs. I err on the side of safety. Of course, as always, your encryption scheme is only as good as your password.