I go there, and hopefully can clear up a few misconceptions people might be having.
Firstly, for specialist, everything he teaches nowadays is relevant to the course. I'm not sure if this is how it's been in the past, but for this first term, there's been nothing extraneous taught.
However, I have reason to believe that he does teach stuff outside of the course in his methods 1/2 course.... Judging from my friend's notes last year, they were taught 3x3 matrices by hand and had questions relating to inverse trigonometric functions (straight from the spesh 3/4 course). Honestly, I don't find this an issue either, because if you're going there the chances are you're finding methods a walk in the park anyway and want to extend yourself. Thus, conceptually learning these things might not be a bad thing after all.
The questions at DHMC are harder than the VCAA exams, but nothing ridiculous. They're probably a level above the Essential text book, and a couple of levels below my school SACs (yes, you read that right).
Oh, and bear in mind that if you intend on improving your CAS skills, dhmc is not the place for you. All homework and exams are strictly CAS free... the word CAS itself is like taboo lol.
The weighting on the exams are weird too.... You get marks solely based on the difficulty of the question. On the latest exam there was a five mark question which explicitly said "don't show working out" and had a single box to provide you answer. So yeahh... I don't think his exams bear much resemblance of VCAA at all.
Hopefully I've been able to give you some perspective now, and if you have any more questions just PM me
