Hi, I just completed my 1st year Bcom following the mathematics pathway so hopefully I can help you out a bit.
I think the general consensus is that the mathematics pathway gives you a better grounding in mathematics itself(hence why the Commerce Student Centre suggests that you do it if you enjoy mathematics), whilst the standard pathway has more of an emphasis on statistics.
A thing that all new students entering the Bcom should be aware of is that the 4 subjects in the mathematics pathway are subjects offered by the Science Faculty, so they will be taken as breadth. This really limits your breadth options, so take careful consideration before choosing which pathway you want to do, especially if you want to learn a language or want to follow a specific breadth sequence.
As a side note, a lot of people who haven't taken Specialist Maths at VCE generally do the standard path as they would end up taking 5 breadth subjects through the mathematics path, cutting off all their level 1 breadth options due to taking all three of Calc 1, Calc 2 and Lin Alg.
I haven't done any subjects in the standard pathway so I can't really say how they're like but in the mathematics pathway Calculus 2 is seen a follow on from Specialist Maths and Linear Algebra is an introduction to abstract ideas/pure mathematics(lots of matrices!)