Hi Paul,
I grew tired of turning wrenches on my riding mower and downsized to a Makita 36V (2x 18V) self propelled mower and I'll never go back, either to a riding mower or to petrol.
Most of my property gets lots of direct sunlight, so I err on the side of cutting the grass rather long, 3-1/2" to 4". The Makita has no issues cutting rather thick grass, though I do make sure I wait until the dew has evaporated.
No fumes, much less noisy than petrol, and I never have to change the oil. I'm positively impatient to replace my two stage, tracked Honda snow blower with cordless once a suitable product is developed.
My lawn is close to an acre, so it takes ~8 5.0Ah batteries to mow the whole lawn. Usually, six batteries are enough, with four in the mower and two on the charger. Hot weather does decrease battery life, but at that point I don't want to be out in the heat either so if/when I find myself getting ahead of the charger, it's a good excuse to retreat to my air conditioned shop for a bit to cool down and let the batteries catch up.
I purchased this mower when I was exclusively on the Makita 18V platform, now that I have some 40V XGT tools I'll probably buy a XGT mower the next time around.