Yes, the SX, even in 177 will be a stronger edge and better in the gates than a 182 AX.
I think if you're truly looking for a the most versatile frontside ski that can hang with FIS skis from other ski in terms of tracking, edge, stability, while only slightly giving up a little bit of rebound, then the SX fits that bill, where the AX would be too much of a drop off from other brands "masters" FIS skis in terms of power across the fall line. (not in tracking or stability through.)
The GS has a little more power across fall line, but is not as versatile.
You can get the D20 plate on it.
Regrettably Jans has overlooked the SX. It can't be demoed in Park City. Actually nobody in Utah has it.
Dawgcatching did a pretty fair assessment on the SX here:
First off, in bumps, I found the SX to be more than passable. It was quite easy to ski, although required more commitment than the AX. It also should NOT be skied from the tail, as it contains a Tigger-like coil, ready to spring. I was able to find the sweet spot on the SX very quickly; it was fluid and relatively easy in the bumps, although maybe 15% less forgiving than the AX. This is a compliment however, as the SX is a powerhouse and there is no way to add energy and power without subtracting forgiveness. I found the SX to be more than competent off-piste. It was a whole lot of fun in bumps; snappy and energetic. Where the SX really shines, however, is on a fast groomed slope. The conditions this day were not ideal, due to the slush, but still, the SX was a cut above everything else I skied. I could load and trust the SX in a way I could not trust any other ski: it had an absolutely locked-in feel when on edge, and instead of getting pushed around by the crud, the SX was pushing the crud out of the way. It was like the old Chuck Norris joke: "when Chuck Norris crashes his bicycle, the road gets Chuck Norris rash". That succinctly sums up the SX. It has the power of a pure carver; the SX is simply unshakable, whereas each of the other skis I tried this day, aside from the WRT, got kicked around to varying degrees in the slush. At speed, I trusted the SX more than any other over the 2-day period. It simply was at a higher level of performance; locked in, powerful, unshakable. I could lay this ski over in a way that I didn't dare with the other skis. The SX allowed me to work the ski; I could run it in big lazy arcs, or dial up the energy and tighten the turn radius for a snappier, more involving ride. I have skied a lot of skis in my day, but I would rate the SX as amongst the best carvers I have ever skied. It is right up there with the nearly perfect MX74 from Kastle, but is obviously a much different ski. I sent the rep a check for his demo pair immediately. If you are in the market for something close to a pure carver, the SX has to be on, if not at the top of, your list.