The shimano wheel is wider at 22mm, the Mavic 19mm. Much has been written on the benefits of wider wheels. The Shimano wheel is more expensive. I would forget the Mavic SL and just go with the regular Elite, which can be procured for way less $$. Same rims, same spokes[Edit:?], different hubs. The weight diff. comes from the hubs where any weight loss is negligible on both feel and performance.
I road a pair of Elites and beat them up bad for a couple thousand miles, like an Irish traveller bare knuckle boxer. They never left true or broke a spoke once, even with the low spoke count. 1550gm is light for a set of cheap factory wheels. Rumor has it lighter riders find them too stiff. They are very responsive, notably more than the Zipp101's I'm currently riding. I've ridden the deep section DA wheels of the version you are considering, and for a deep section wheel they were pretty comfortable, the shallower rim of the C24 probably more so. During a race, I hit a BAD pothole on the deep section version, the CRACK was loud enough that almost every rider close to me in the pack lifted their head and said WTF!? There was no damage to the edge of the wheel and it remained true. They are also a low spoke count wheel. I weigh 170lbs.The deep section version didn't seem to do so well on 50+mph descents.
The Mavic front hub skewers need to be greased after riding in the rain (yes the skewer), otherwise a clicking noise that was attributed to all kinds of things like the pedals, crankset, handlebar connection to the stem, would occur under load until after some serious troubleshooting. Skewers aside, the DA hubs are significantly better.
There are many wheel options, I have commented only on the wheels you asked about. Personally if I had the cash I would go for the DA wheels. And personally I would go for the clinchers.