I just checked out the autos and I'd go with the SLs. I didn't take them on the slopes b/c I had to decide whether I would return them or not but these are the reasons why I'm passing.
I've ridden Datas, Forces, Force DLX. The only major plus I saw was the super cushy footbed on the Auto. The ratchets on the autos start slipping at a lower tension and were actually a big pain to release. If you like to crank down your straps these are frustrating. As an experiment, I threw on my ratchets from raidens and those let me crank down way tighter, and the release was smoother. But moving on.
The strap is actually very comfortable, but does not feel as responsive as the Union strap. This has alot to do with the ratchets, but also due to the fact that it tends to squeeze together and fold. This is great for freestyle mobility but I don't see it happening when you're charging. The back is pretty nice, no major complaints there, but I felt I liked the union back better. Maybe I'm just used to them. Also, there's no forward lean adjuster on the backs, you need a screwdriver to set the lean. It's a very clean solution, but it's no good if you like to switch your lean depending on the runs you're taking.
Lastly, No adjustable heelcup. You get some offset disks so you can shift it forward or back a preset amount, but I couldn't get it right enough, and I feel like on a 250 dollar binding, you should be able to get your stance exactly where you want it these days.
The auto toestrap works fine once you get it set up (you have to make sure not to use up all of your cable when cranking on the heel strap. I know burton avenger hates on Union and loves K2 (he's all about the formulas though) but I felt better overall on the unions. The one major area union gives it up to k2 is in Base padding, the harshmellow/canted footbed is really badass. I think the Force SL is close but Harshmellow really works as far as I can tell. I rode a board (2009-jibpan 158) with harshmellow and union forces and it was the dampest ride I've ever experienced. Loved it in the chop.
My 2 cents.