The key elements are negative buoyancy steels and at depth as indicated in my comment. Take 2 Worthington LP85s and go down to 100+ feet in the Great Lakes (temps in low 40s/high 30s). Here are basic facts that relate to the OPs pics:
(a) W/o a butt plate the cylinders will hang low as observed in the pic; with a ~1/3 full cylinder, it'll be less pronounced (I've tried that) but a butt plate is a must.
(b) In cold waters with very thick undergarms, many will need to add extra lead. Obviously the exact amount differs by person. The drysuit is there to take the squeeze out, not for buoyancy control (unless you follow a PADI drysuit course). 100+ feet down, your wing will need to be inflated close to max capacity. A wing with lift in the mid-40s or higher is more adequate for these conditions. I'm not talking generically but specifically to the environment that I mostly dive in and, it seems, the OP does from the initial description. If that's not the case, my comments are not relevant.
(c) Adding a deco/stage bottle makes a difference but it's not a whole lot. The first stage weighs about 2-3 lbs depending on model; an 80/40 AL cylinder adds slight negative buoyancy when full.
Just enough for 2 worthingtons? That's just not accurate.
---------- Post added September 16th, 2014 at 04:43 PM ----------
I think a lot of the info being thrown out is not accurate. We've been diving all sorts of steels (Faber, Worthingtons, 72s, 95s, 100s 120s) with the Stealth all summer. With stages even. And we've never used the butt plate. A lot of the misinformation is from people that do not know how to set it up properly. Others see this and take it a gospel. As with any other system, for it to work properly, it needs to be set up properly.
I'm only conveying my experience and how it might relate to the pictures posted by the OP. I'm actually a big fan of Stealth 2.0 but for the 36 lb lift which in the environments I described I find lacking. If others can get it to work w/o a butt plate and not look like the OP in the pic (good horizontal trim but the bottles are hanging low) for the situation I described, then they must be doing something different. It may help to specify what that is which, to me, seems to violate some laws of physics.
---------- Post added September 16th, 2014 at 04:55 PM ----------
I dove HP100 steels last weekend and there was no way I was getting them to trim parallel with my body when they were full at 3500 psi while using the square rings or any waist band d clips. Sure once they dropped to 2000psi, they were much easier to align. But that was after an entire 1st hour dive hanging below my hips instead of along side them. ...
Some seem to claim they can. Sure, I've tried using medium size bolt snaps. It helps somewhat. Yea, but try manipulating those with thick dry gloves in cold water. Indeed, misinformation seems to be thrown around by folks without specificity to back up their claims. But I remain open minded and willing to hear how they got HP100 cylinders parallel w/o using a butt plate.