SLDL's do not hit your back hard enough for me to agree with you casual. I love full ROM deadlifts but nothing kills your back like partial deads with a wide grip, here's a snippet from Dave Maurice for those interested:
To perform the wide grip partial deadlift, set up with blocks or in a power rack so that the bar is anywhere between just below your knee caps to the center of your knee caps. To get your grip width, flex your lats like you want to show off, and then put your straight arms out and resting on the lats (you'll look like a dork). Anywhere between there and arms about 45 degrees out from your body will work. Use a pronated grip and use straps. The performance of these is just like that of a regular deadlift from the midpoint position, only with a wider grip. To really get benefit out of these, the lifter has to be good at fighting to pull the bar back at all stages of the lift. None of this "arm hanging down" nonsense. Not only can that lead to back rounding, it can be very hard on the shoulders. Start with the bar right against the knees, and drag the bar up and down the thighs. Try to think row - you can't row such a heavy bar, but you can sure try to pull your shoulders back and try to to touch your shoulder blades to each other. Again, this is just like a deadlift; only your grip position and range of motion has been changed.
Compared to regular deadlifts, these hit the upper back harder, the middle back as hard or harder, and don't give up much for strengthening of the erectors. At the same time, they take enough off the pounding the hips and low back get from regular deadlifts so as to not interfere with squats in those individuals that find squatting and deadlifting heavy in the same week to be too much. By the same token, since these don't do as much for hips and thighs as conventional deadlifts, the lifter better be really getting the job done on those parts with squats or leg presses.
Compared to a conventional partial deadlift, these will do more for the back with less spinal loading. Compared to snatch grip deadlifts, they allow heavier weights over a similar range of motion for the back muscles, while reducing the odds of aggravating the low back. Most importantly, they offer even the clutzy or short armed individuals a way of loading the muscles loaded in a deadlift or dynamic pull in relative safety.