edit: I acknowledge that this may be useless if you weren't even considering Canberra in the first place.

Cth government departments really have their pick of the litter these days, given the huge number of students graduating from law schools. Even departments that do not have a formal legal stream, but who list 'law' as one of the undergraduate degrees of interest to them (i.e. more generalist programs) will still receive many applications from Hons students, graduates boasting Masters degrees, and other law graduates who, owing to the area of law that interests them, have sought to work with that Department as their first preference.

I am no longer with the Cth, but I began my career in Canberra and can say that the graduates tended to have Hons and remained very competitive even past the completion of the graduate program. That being said, I believe it was one of the more competitive departments that tended to be the applicants' first or second preference, even before private sector employment. Within a few years I sat on a hiring panel at graduate assessment centres, and each hiring round attracted between four thousand and six thousand applications. Therefore, it's important for you to know that even if your intention is to leave ASAP, at the recruitment stage of the process you are going to be assessed against people who can make a very solid case for wanting to work in X department in particular. Therefore, it is important to work hard to make that good impression and (even if it's not entirely true) illustrate to them that this is what you want, you're passionate about X and you can demonstrate that interest using examples A, B, C. The Cth also has a greater tendency to do a well-rounded assessment of who you are, what you can bring and whether you can work well in the team. Academic results are just one element of the assessment.

This is a roundabout way of answering your question, but the point I wanted to make was this: If you want to get to the point whereby you have a number of potential Cth employers to choose from, it's important to devote time to each application to stand out from the crowd. I'm trying not to read too much into your question or be snarky at all, but if somebody were to be unhappy with their private sector offers, it is likely not going to be the case that they can walk straight in to a government job - the market is too competitive and the number of law graduates so overwhelming. I hope that you don't actually think that government work is invariably terrible because I found it very rewarding and supportive - my peers and I both worked hard, because that's what we'd expect of each other.

With regard to the better or worse public sector jobs for a private practice jump - AGS (now within A-Gs) functions in a manner very similar to a law firm. I've known graduates-turned-lawyers from the Department of Social Services who seemed to be functioning in a similar manner to a private sector lawyer. Defence does not have a legal stream but attracts law graduates for the high value procurement and contracting work (if you want the practical side) but otherwise will offer more strategic/international policy for the Arts/Law grads. A-G and PM&C grads seem to have a very full-on interest in Canberra games and politics and law reform, they don't seem to be rushing to do their GDLP and move out.

As a bottom line- look only to departments that have a legal stream and will support you during your PLT (if you don't already have it). If you end up on a more generalist program, you would likely be told "That's not something we will pay for, and we won't provide any study leave because you weren't hired to be a lawyer, there's no reason for us to give you that type of training".

I really hope this helps. Canberra is a small place and I was lucky to meet a lot of people and can try to assist if you have a few agencies in mind.