I can't comment much on pushing this tent to the limit because I haven't done so. However, I wanted to fill in more of the details. I'll try to focus on things people haven't mentioned.
First, let's get some background on me - I'm a 5'6" male who backpacks in 40-80F weather, usually in dry, windy conditions. The only other tent I've used is the REI Half Dome 2 which costs much less at full price than the Arx-2. I set this thing up the "normal" way - tent + poles + rainfly.
PROS: The tent itself is very "open" with lots of mesh if you want to sleep under the stars. The bent poles give you a great deal of headroom, and with the gear loft + 6 interior mesh pockets (if I remember correctly), you have a ton of space to store little items within arm's reach. The tent is HUGE for me - I can actually store my pack at my feet and still sleep comfortably, but I'm a pretty small dude. My companion is a 5'3" female, and both of us sleep parallel, in the same direction, without any crowding issues. As far as you tall people go - I've slept with my head jammed into the side of the tent. The material gives way easily and it didn't keep me from sleeping at all. I
The rainfly is great. There's one vent in the top center of which I think is quite adequate and is angled to keep rain out. I've taken it out in light rain once and it performed great - no leaking. I have no idea how it will perform in a heavy downpour. The rainfly is not just secure, but easy to secure. Once the rainfly is on the poles, you attach it to the tent with quick-release plastic buckles. I like this much better than the Half-Dome's system of grommets over the ends of the poles. The whole process up putting up the tent just feels slightly smoother and faster. This doesn't really matter, but I'm usually tired after a day of backpacking so it's nice to be able to spend minimal effort and time setting up camp.
Then, you put stakes beside the tent for the vestibules. There's a friction system that makes it very easy to get the vestibules really taut. And finally, like most tents, you can unzip the vestibule, roll it back, and have it held there like an open curtain. The vestibules aren't massive, but there's enough room to store your boots and pack without issue. Flapping of the rainfly in moderate wind is minimal.
By the way, the included stakes are good - strong and easy to drive deep. It's a minor detail but I thought I'd mention it anyway.
CONS: Frankly, the only one I can think of is that there's no included footprint. However, a 5X7 tarp can be found for $5 and works perfectly fine if you're cool with it not being secured to the poles. It's even covered by the rainfly, so you probably won't have issues with water getting under it.
I have to admit, also, that setting up the carbon pole always makes me nervous. It takes some firm force to get set up and as a cyclist, the sight of carbon bending is terrifying. However, I have had no problems with it so I can't really count it as a con.
I found that the sizing is somewhat off on these. I measure 17" from C7 to the iliac crests, but a medium fits me perfectly (allows for me to position the load lifter straps at the 45 degree angle shown in REI backpack fitting videos). Small was way too small.
Note: I'm a 5'6" male with broad shoulders and a barrel chest. I don't know if that affects the sizing.
EDIT: Now that I've done some more research, it seems like packs around this 36L size in general may not be designed to have the 45 degree load lifter strap angle. That said, I've put the pack through some overnights now and the medium fits me pretty well, although I'm just about maxing out the straps on the waistbelt and load lifters to get a proper fit.