My ATBs arrived today so I'll give you my initial impression.
Boot shell
First off the translucent red looks way cooler than I thought it was going to.
I'm liking the look of the boot.
The boot shell as the same as any of the other boots in the UPZ line.
But the material is so much softer. So soft in fact that even though my feet are phenomenally screwed up (flat, bone spurs, jutting out ankle bone) when I put the boot on and tightened everything down I was having difficulty telling if I would need any boot fitting done.
Boot heels
The shells came with the heels already t-nutted for installing step-ins.
Thank you UPZ! I know this has been an issue for most of us here.
The boots come with riser pads, screws (#2 Phillips) and locknuts for the installation of step-ins as well.
UPZ calls the riser pads "shock absorbing plates" and has supplied them to be installed between your step-in and the boot shell.
My personal opinion is this acts more to shin the step-in in line with the toe piece than it is for shock absorption.
All mounting screws on the boot, with the exception of the eight screws supplied for step-ins are torx heads in one of two sizes.
UPZ supplies two torx keys for all of these.
I removed the boots existing heels, which required twelve screws for each heel, and installed Fintec heels.
Boot toe piece
I mentioned in a post above that it looked like UPZ had modified the toe block because there was apparently some issues with them fitting into some bindings.
I had heard there was a problem with Bombers in particular.
I can confirm that there is no interference or issue with this years toe piece and a TD3 step-in.
The toe pieces are attached with a beef screw but are not t-nutted.
Which based on the design of the toe piece, boot interface I don't think is a problem.
If you have issues with this take it to another thread please.
Both the toe and heel have a much more aggressive sole which looks like it would help provide stability which hiking.
Unfortunately I lost half of this when I installed the step-ins.
Boot tongue
The red tongue is really soft. In fact the only way I can really describe it's consistency is rubbery.
This tongue will not impede the flex of the boot in any noticeable way.
In fact the tongue folded easily out of the way when I was putting the boot on.
Spring Mechanism
This appear to be similar to what is on my RTRs though I suspect the springs are much softer based on how much I can flex the boot.
Liners
The ATB uses what are called a Flo adaption liner which is definitely different than the ones used in my RTRs.
The tongue is much softer than the RTRs, and doesn't impede the boot flex. The heel cup held my heel snuggly enough that i couldn't notice any movement.
I was initially going to replace these with a Deeluxe 141 because I have had nothing but problems with liners with tongues, but I think I'll hold off and give these a shot.
Stiffness
Ok I'm 230lbs, and having been riding in, and flexing the snot out of RTRs, I know how to put pressure down and flex a boot.
The boots are literally flexy enough to hike around in! I then stepped onto my AM board on the carpet which is set up with angles of 50/45 and TD3 step-ins.
Laterally the boots seem to be stiff enough that, at hardboot angles, they would allow me to respectably carve a turn on our Rocky Mountain snow and are soft enough forward that I could absorb chop or suck up huge landings.
Read as "I could fles the sh!t outta 'em".
As a comparison laterally they feel like a Track 225, though forward and back they feel much softer because the spring allows a controlled forward and rearward flex.
My opinion is with these I probably wouldn't require Sidewinders.
Conclusion
I'm a 230 lbs freak who has given up riding softboots completely.
I ride UPZ RTRs with Fintecs into TD3 step-ins on a 173 Schtub for carving, but have been trying to put together a good AM set-up that fill feel floaty and surfy.
I bought a custom 167 Donek last year outfitted with TD3 Step-ins and tried it with a set of Deeluxe 225s last year, and while it worked, no amount of boot fitting was able to allow me to ride the Deeluxe boots for longer than three hours with out pain.
I purchased the ATBs specifically for AM riding.
The intention is mostly for light carving, off trail, trees, pow, and jumping.
Personally I think these boots could be great in those applications.
Perhaps with a slightly stiffer tongue it might even acceptably float between carving and AM really nicely
Puddy Tat
nurse ben
I have a few more days in the UPZ ATB, so I figured I could chime in 
I bought the 2011 white ATB last summer from Bola, rode them for a couple weeks at Abasin and Loveland boot packing.
The original liner fit small, so I ordered a replacement and in the meantime used my tele liners, some thermowrap Scarpas.
I was able to get a good fit and since I'm still waiting on my replacement liners I have cont to use the Scarpas.
I found the ATB to be quite soft when unlocked, so that meant I had to rode them locked, which was fine in firm conditions, but really not that great when the snow was soft/loose.
So over the summer I puchase some older UPZ RTR with black and grey tongues. I replaced the sole with the ATB sole and then swapped tongues between the two boots, putting the red tongue on the stiffer RTR and the black tongue on the ATB.
I rode both boots one day at our local WSOD, then three days at Brighton (Utah).
I can't say which boot I like more, they have some different riding characteristics, the RTR having a stiffer shell so lateral flex is less than the ATB, but with the stiffer tongue in the ATB it seemed to help with overall stiffness in the ATB.
I ended up preferring the ATB with the black tongue for all around riding, though I could easilly ride the RTR with red tongue and be quite happy; the RTR setup would be a nice way to get an ATB on the cheap
I have a couple concerns with the UPZ heel as the four bolts holding the heel in place are not that secure.
Because the heel itself, not the shell, is retaining the heel bale, there is a lot of pressure on those four bolts.
On the boot side, the Tnuts are pretty solid, but on the heel side the bolt heads are not that secure and could pull through the heel block.
I can't see an easy fix other than modifying the heel block with some metal inserts to better retain the bolt heads.
I did reinstall the RTR heel block with epoxy to reduce play between the boot and heel.
Also, if you do choose to order some ATB soles for an older pair or RTR, keep in mind that you do need to do some dremel/razor knife work in order to make the toe fit AND be sure and order the rubber "half moon" that fills the slot in the boot shell so the bale stays put.
I'll post some pics when I get a chance.
Great boots!!
