I'm doing all my services for the same reason. Rather pay for fluids than getting my car damaged, or a fluid change done wrong, like it has happened numerous times.
I recently did a tranny and diff fluid changes, along with a full brake/clutch bleed. Bought Royal Purple Synchromax for the tranny and 75/140 Max Gear for the diff. No more crunching behind, and tranny shifts better, so definitely recommended. I'm still using TWS 10/60 during warranty, but will switch soon after that; it's total overkill when not driving the car hard, especially in winter. Good luck man.