Decks of modern plastics are virtually indestructible. Finally, plastic catcher bags are generally more durable than cloth bags. Self-propelled rotary mowers use a power drive mechanism. These machines require the operator to squeeze a bar or a lever to engage the mower. If the lever is released, the drive system and blade both stop.
Some models abruptly start, while others move forward gradually.
The latter is much easier to control. I prefer rear wheel drive over front wheel drive. Mulching mowers are the basic mower for most home lawns today. They burst on the scene about a decade ago, once American communities began to exhaust landfill space. Their capacity to mulch clippings so you can leave them in place is useful if you don't want to collect them.