Your lawns seem to get a lot of growth between cuts, do your clients try stretch out the cuts as far as they can? I try not to have most lawns any longer than 2 weeks, a few are weekly. Id hate to be spending $200 + per week just to have my lawns cut but in some cases its the only way.
i guess being in qld you have more rain than us down here?
Im still running with the mulch kit atm, but within a month or so we will start getting too much growth for me to continue mulching. I dont find the blades work as efficiently with mulching, i get straglers left behind (weeds & tall grasses) , unless cutting a nice lush thick grass, in which case the cut quality is very good.