Pros
Good starting pay. MAY have work life balance depending on which division you land in. Most seniors are easy to communicate with and willing to teach. Stable even in poor economy, similar to government agencies.
Cons
Career progression is snail, esp if your highest qualification is bachelor degree, unless you are super exceptional and more importantly your boss SEEs your value (no see no count). Don't expect good WLB for most technical roles, if you want WLB with relatively faster promotion go to DSTA (same starting pay, or better in certain roles). Get ready to be tanned. Abundance of red tapes, be careful of where you thread. Niche line of work, be here for 5 years and you are in for the rest of your life. If you want promotion, and is willing to stay for the rest of your career life, recommend to go for masters. 9/10 principal engineers and above hold master's/phd. Last note, DSO is not a stat board / public service, it is a considered a private company, thus no civil servant bonus.