In the first post, there was talk of 600sqm of lawn area. With a width of 33cm, that results in 1800m of cutting length (600 / 0.33). The automatic sliding mowers usually have 3.6km/h. So the pure mowing time of 30 minutes is possible with perfect cutting width coverage. With a 52cm cutting width mower, that would be 1200m and thus 20 minutes pure mowing time. Converted per month, that rounds up to roughly 1 hour more time per month.
But you certainly can't go wrong with a [sabo]. I would have still chosen a larger mower.