I did my undergrad in maths here and loved it - will move onto honours next year.
Like any uni, the quality of teaching by lecturers vary a lot. Comparing the classes I've taken, I've done 12 maths courses with very positive experiences with lecturers, and 3 math courses with lukewarm lecturers. I don't believe I've ever had a single lecturer that I would say is horrible across my entire degree. For statistics, I'd say it's 50% good lecturers and 50% lukewarm lecturers.
I was very satisfied with my mathematics education here. Under the new curriculum, new students must take a project unit, which can be a good or bad depending on how you value projects as opposed to conventional lectures (I much prefer the latter).
Research here is fantastic; you can literally casually approach an academic and talk to them about their research, and they'll very likely end up asking whether you're interested in getting involved. I'm currently in the process of publishing a mathematical paper, and some of my other friends have done so too (few, since it isn't easy, but definitely doable for some).
Regarding the Master of Mathematical Sciences, I strongly recommend going for an honours year if you can, since it's cheaper and has been around for ages so it's well-established. I recall that last year, they mentioned that the Masters of Mathematical Sciences isn't subsidised, but that may change in the future.
