I use DbFriend for:

- clean organization (I can put my files anywhere on disk, not just where SMSS says).

- clean, repeatable scripts (SMSS script options are many and if I forget to check/uncheck an option, all my scripting time is wasted)

- comparing against Production (again, clean scripting makes this a reliable DIFF)

- DATABASE FIND & REPLACE

- working in my environment of choice (VS 2008)

- encourages me to THINK about my SQL assets as compiled code, that I have to RUN against a SQL box first, then exercise using SMSS (and with dual monitors, this is a very fluid workflow)