These are my totally
subjective comments.
For the record, I have a Ranger LTD and a friend has a Mares with Airtrim - not sure if it's the Dragon - but I have seen it up close.
I don't think the Mares takes doubles if that's something you'd be interested in later. With the Ranger, there's a mounting kit for them or their optional backplate for additional stiffness.
The Airtrim just strikes me as more un-needed failure points for the sake of convenience. DIR and other schools of thought on SCUBA emphasize minimizing failure points when diving, this seems contrary to that notion.
The exclusive "Twin Exhaust Valve" technology, patented by the Mares research laboratories, allows the Airtrim® deflation button to simultaneously control both of the pneumatic exhaust valves: that way,
Afaik, there's two extra little tubes running inside the jacket to the pneumatic dump valves. Which also suggests more complexity. There's also two check valves in the dump valves so that water can't enter the BC.
Of course the big advantage is that it always vents air through the appropriate opening without having to think about or adjust your orientation. With the Ranger LTD, there are times when you have to put your left shoulder higher to vent from the pull-dump on the inflator.
My dump valves consist of a flat rubber diaphragm with a spring and attached piece of nylon string to pull each one. Granted you have to decide which one to pull, but it's not rocket science.
Air Trim System, Elimination of your bulky corregated hose makes for the most streamlined configuration
I just don't see that a single inflator hose, properly secured is such a drag through the water. In my opinion, they're addressing a problem that doesn't exist for the sake of convenience. I could probably make a case that the surface area of the airtrim mechanism is close to that of a corrugated hose.
I asked my friend once what she'd do if the
inflator failed nowhere near a Mares Dealer. Her answer was she'd rent something else. The Ranger has a standard 1" inflator hose and a much simpler inflator mechanism, I fixed mine once when it was sticking by banging it on the side of the rinse tub while swirling water thru it. Lost one dive that morning. I also can buy a replacement generic inflator hose just about anywhere as needed.
With my Ranger, I can visually inspect my corrugated hose leading right to where it plugs in to the bladder, my friend has to un-zip hers first somehow to do the same afaik. So you're less likely to notice a problem during a quick visual inspection.
Also there's a separate inflator hose that's tucked into a pocket in the event that you need/want to do manual inflation. Another dive buddy of mine does this every pre-dive so he doesn't use tank air to inflate his bc prior to jumping. Seems like that would be more difficult with the Mares.
On the plus side, loading weights into the Mares seemed easier than my Ranger. Esp. when already wearing it. And they have a nice positive click when locked in.
I use the yellow bags with my Ranger (provided with the LTD) for any all/weights, I've used lead shot and various combinations of soft and hard weights - none has ever gotten past the ripcord. A buddy had a 1 or 2lb. bullet weight drop through his ripcord once when we jumped.
my .02..