A 5 foot hose is fine for open water use, but is too short for penetration dives where you might have to exit in sequence. It is also too short for the techie wrap around your body type of configuration when wearing it. However, there is nothing wrong with a 5 foot hose for open water use.
Yes, while I'm a very frequent diver, I'm strictly recreational, open water and not interested in tech or penetration diving. While I completely understand the need for my techie cave-diving buddies to have that long seven-footer all wrapped around, I really have no need of that. But I would like to streamline a bit, and I like the underarm configuration better than over-the-shoulder, which is why I'm considering the five-foot flex hose for my main reg.
Given your equipment at present, you might want to consider the following idea. Sling your pony like a deco bottle. In an OOA situation, once all the panic and confusion is settled, unclip the pony and hand it off to the OOA diver. No necklace should be used because you want to hand the whole thing off.
Believe me, I tried all the various pony configs: slung, cross-mounted, tank-mounted, bagged, left-sided, right-sided, upright, inverted, valve off, valve on, shiesh... The main problem I had with the slung configuration is that, as a photo guy who is often doing macros, the slung pony simply gets in the way too often, and risks damaging the reef given how close I hover. Given that my primary purpose for the pony is for bailout use as a solo diver, only secondarily for buddy diving, I have ultimately found I prefer the configuration like this: bagged, left-sided, using the Zeagle Razor combo valve/first stage for streamlining and reliability (one less seal) and compact size (valve + reg together still smaller than most valves by themselves), short hose routed under left arm, necklaced reg.
While not as easy to hand off as a slung bottle, having it bagged instead of hard-mounted to the tank still gives me the option to remove it fairly quickly & easily by popping just two Velcro straps off the top of the bag, yanking the reg off the necklace, and handing off to a buddy (or for use myself that way if my main rig becomes entangled and I need to remove my BC), but it's normally completely out of the way and streamlined, unlike slung.
The DIR guys may go nuts, but I won't. If you need too many gadgets to get comfortable something more basic is wrong.
Oh yeah, as far as DIR goes, I'm definitely a DIW diver, "Doing It Wrong", and proud of it! Lots of DIR no-no's: I'm happy as a solo diver (working towards the SDI Solo cert), and I prefer a highly ideosyncratic rig that works for ME and me alone, sticking with BC over BP/W, I
like the ProQD lever inflator/deflator, I
like my Air2, I
like my splitfins, no long hose, I'm mounting my pony left, with the hose coming under my left arm, etc... definitely DIW as far as DIR is concerned!!!
Again, I understand the need for DIR standards in techie diving like the WKPP guys do, where it's all buddy-based and you need to know not only where all your own gear is, but where your buddy's gear is too. But for my style of solo (or with unreliable "instabuddies"), photo-centric, open-water reef diving, at recreational depths, DIR is waaaay too stringent and doesn't make sense to me. That being said, I do have tech buddies and have applied many of their ideas: I'm all-DIN, I carry not only a knife, but also a Z-knife and shears for extrication, Goodman light, leg pouch, etc... I even mounted a crotch strap to my ProQD (helps
tremendously for those upside-down photo shoots!). What's important to me is that my gear is intuitive and obvious for ME to access and use, since I'm not counting on a buddy.
>*< Fritz
DIW Diver