Obviously easier to answer this question after round 8 hutstar! Far easier to point out negatives when we're playing badly...
But I'll give it a go:
Defensive (back half) structure has be always been good, the stats back that up, even when we're losing. Campbell spending time at half back has been a great move, the development of Chaffey, Kellaway, Newman, Holland to CHB was a very good move, pre-knee injury. Generally I can't be too critical of our defence, especially when all fit and well and playing with some confidence. Kick outs have been good, in fact I think we are right up there for creating scoring shots (for us!) from defensive kick-ins.
Development of Coughlan and recruitment of Johnson has improved our midfield, as has Stafford. When all fit (and that hasn't been very often) the handling of Stafford and Ottens, along with Cogs, Rodan, Johnson etc through the midfield has been OK. Hard to make judgement here as Stafford, Ottens, Campbell, Hall have missed large chunks of football in the past two seasons. They're not at top 6 stage yet but I think the midfield structure is on the right track, we just need some bigger bodies and smarter heads in there, plus some luck with injuries would help.
Off field he's been one coach that's had the guts to drop players for disciplinary reasons (Vardy, Ottens, Daffy, Richo) and set standards for off field behaviour. Sorely overdue and seems to have worked (touch wood!).
When we've been winning, I've been impressed with our much quicker ball movement and direct kicking. The flicking the ball around by hand that frustrated the bejeezuz out of everyone under the Giesh has been largely eradicated, thank goodness.
I'm sure there is more but that's all I can think of off the top.