They're not actually mowers at all - they're small cars that only go 25-30mph - even with all that power. At $13.5k that's bordering on insanity - even if they are a bit of fun. The most useless thing I've seen in ages, but I'd still like to have a ride on one! Even limited (because the COG is pretty high by the looks of it) to low 30's, acceleration would be rather brisk.
What fun.
You'd really want a completely unallocated & spare $14k to throw away, wouldn't you? Not in my lifetime unfortunately.