Courtesy of John S. , Blue Ribbon Eggs, Franklin NC
There is no one solution that always works for every problem, and there are often several different solutions to any single problem.
Wally is dead on. The two big advantages to formal raised beds are elevating the soil temperature sooner and quicker, and better drainage for overly wet soils. If drought is your problem, raised beds certainly aren't the solution. Additionally they make tilling with machines difficult if not impossible. If your soil is 'ideal' you could till with a broad fork, but still that can be a pain.
Over head sprinklers have huge water loss due to evaporation and are usually 'non-specific', IE: water everywhere. Your best bet, in my view, is a well designed drip system.
I knew nothing about them, called up DripDepot (dripdepot.com) and a lovely young lady helped me design a perfect system for my quarter acre of blueberry bushes in about 20 minutes on the phone. She sent me the stuff, and it took an afternoon to install - no tools but scissors and a hand punch, all hand tightened joints. Now I water 200+ berry bushes effortlessly, whreeas before it had taken all day (8 hours) once every week or two for the season. The system I have is convertible to gravity feed if I wish (I have low water pressure), by simply removing the pressure regulator from the line. I bought it 3 years ago and spent $239 including freight from Oregon to the east coast.
As we all know, the SPIN principle is to reduce labor, reduce costs, increase efficiency and increase profitability. It works from the Great White North to equatorial Africa and Central America because those principles make sense to everyone everywhere on the planet.
You need a tiller because it is cost effective and efficient (money and labor), you need a cooler of some type for the same reason, you need a watering system (see your SPIN intro book) for exactly the same reason. You can install a drip system for about the same price as the good quality hose you would need to drag around.
If I want a raised bed (some years are very dry and I don't, some years it's very wet and I do) I use a simple iron rake and rake the soil up in to 10" high beds (low mounds) that keep their shape for the season. No boards, or walls so I can till and reconfigure whenever I need to. It seems somewhere along the line raised beds became the default setting for anyone wanting to grow food. But there is no production advantage to them, and in fact, they mostly work against you, not with you.