I'm at Melbourne and I've taken a few subjects from the human sciences area (anatomy, physiology, pharmacology) and I have been extremely pleased with how they are run (and friends who have completed neuroscience subjects have found them to be very good). Something that Melbourne does that Monash doesn't is the body donor program. If you are interested in taking subjects in the anatomy/human structure and function (which you may if you are considering neuroscience), you will get to look at real human specimens and at a third year level, actively participate in dissections of cadavers.
I would suggest thinking about a few majors that you are interested in and compare and contrast between the universities. Many people go to university with an entire plan only to realise that they want to go down a completely different path (for instance, I wanted to medicine when I first went to uni and after first year I realised that I really enjoy chemistry and am now majoring in it)
I'd recommend reading through these threads
https://atarnotes.com/forum/index.php?topic=43031.0https://atarnotes.com/forum/index.php?topic=43048.0They are subject reviews, written by fellow ATARNotes users and I've always found them to be very good at encapsulating the subjects. Read through them to give you an idea of both universities and compare similar subjects between the two.
Good luck with your decision.