There is a reason
There is a very specific reason why I haven't chimmed in on the comparison.........I'm not done.....

I think extended riding gives you more of a feel of the bikes, than parking lot rides, of course, but even more than slightly extended rides too. Lets put it this way, I've had less problems with the 5th AIR than the Romic's that I've seen on the 5-spots. Granted, thats not DT's problem, but by the same token, at the beginning of the year, I seriously doubted the 5th Air's durability and even tried in vain to get a coil onto it.
The 575 literally sprints uphill, period, when the 5th is set up right. It hooks up better than my hardtail, and the frame is less than 2 pounds heavier than my hardtail. On the downhills, unfortunately, I haven't been able to compare an apples to apples test of the 5-spot and the 575, because I can't keep forks in long enough for them to have the same forks. The 5-spot usually has a Z1, Z150, or a Maverick on it (by far my favorite recently), and the 575 I've only ridden it with the Talas. Even with this apples to oranges comparison of bikes, the 575's rear suspension soaks up descents and handles drops every bit as well as the 5-spot.
I haven't seen brake jack, period, out of either, but as I've said before, you need to actually use the brakes to experience something like that. The only thing I can see as a weakness of the 575, is lateral stiffness. And I say it as a weakness only because "in comparison" to the other competitive bikes I've ridden a lot (X-5 and 5-spot), I can feel a bit of lateral flex in the 575. In order of laterally stiff, it goes X-5, 5-spot, 575. In quality of descent for rear suspension, just the opposite (575, 5-spot, X-5). As I also said before, I believe with a longer travel fork on this bike, it will be even more of an impressive descender.
Don't get me wrong, there were problems with the 575, but mostly my own doing. For at least 2 weeks, I continually redished my rear wheel because I thought it was rubbing on the chainstay (Its a 2.3" UST), due to the low air pressure. However, I neglected to look for the simple solution first, that being a slightly too long front deraileur cable, that rubbed during deep compression. The second issue I had was rear cable routing. I couldn't get the over the bottom bracket to work very well, during deep compression, as it would ghost shift from either being too tight, or getting held up somewhere, and it was starting to cause a great deal of cable rub. I finally went back to my original routing under the bottom bracket, and haven't had a problem since. I know its not optimal, but it works.
I've tried different sized stems, riser bars, wheels, tires, and brakes on this frame, and by far, my favorite combo has been a 1.75" riser with a 90mm stem, 2.3" UST tires, and Hayes Hydros. I'm on a medium and I'm 5'10", and a 30" inseam. This does give me a set back position, which optomizes the dowhills, but the bike sprints uphill, and I haven't had a problem standing up in the cockpit and getting my weight forward, if I need to. I have some Juicy's that came with the bike but when those wavy rotors get wet, I can't sneak up on game trying to cross the trail, and the pistol in my pack is getting bored (I put that last part in there to see if people really pay attention to this). I've tried slightly filing down the rotors, and it helped, but they are still noisy.
To make a short story long, the 575 has impressed the hell out of me, in many ways, and its definately a bike I look forward to seeing what Yeti does with next year.
Without a doubt, when it comes to best trail bike for around 2k, the 575 gets my vote. I'd have to leave a wheelset and crankset off the 5-spot and X-5 to get it around 2k..........